Epoxy resin molding material for sealing use and semiconductor device

ABSTRACT

1. An encapsulating epoxy resin molding material, comprising (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler, wherein the inorganic filler (C) has an average particle size of 12 μm or less and a specific surface area of 3.0 m 2 /g or more.

The present application is an application with priority claims based onJapanese Patent Application No. 2003-103346 (filing date: Apr. 7, 2003),Japanese Patent Application No. 2003-103357 (filing date: Apr. 7, 2003),Japanese Patent Application No. 2003-103435 (filing date: Apr. 7, 2003),Japanese Patent Application No. 2003-103438 (filing date: Apr. 7, 2003),and Japanese Patent Application No. 2003-103443 (filing date: Apr. 7,2003). Specifications thereof are incorporated herein for reference.

TECHNICAL FIELD

The present invention relates to an encapsulating epoxy resin moldingmaterial and a semiconductor device.

More specifically, the present invention relates to an encapsulatingepoxy resin molding material excellent in filling ability suitable as anunder filler for mounting a flip chip. The invention also relates to aflip chip package type semiconductor device which has no molding defectssuch as voids, is good in reliabilities such as reflow resistance andhumidity resistance, and is encapsulated by the above-mentionedencapsulating epoxy resin molding material.

BACKGROUND ART

Hitherto, in the field for encapsulating elements in electronic memberdevices such as transistors and ICs, encapsulation with resin has beenbecoming the main current from the viewpoint of productivity, costs andothers, and epoxy resin molding material has widely been used. This isbecause epoxy resin is good in balance between various properties, suchas electrical property, humidity resistance, heat resistance, mechanicalproperty, and adhesive property to inserted articles.

In recent years, a phenomenon that electronic parts are mounted on aprinted-wiring board at a higher density has been making an advance. Inconnection therewith, about semiconductor devices, surface mounted typepackages have been become the main current instead of conventional pininserted type packages. About surface mounted type ICs, LSIs, or thelike, the package thereof is thin and small-sized in order to make thepackage density high and make the package height low. Thus, theoccupation volume of the elements in the package has become large andthe thickness of the package has become very small. The elements havecome to have a multifunction and a large capacity, and accordingly thearea of the chip therefor and the number of pins there for have beenincreased. Furthermore, on the basis of an increase in the number ofpads (electrodes) therefor, the pitch of the pads and the dimensions ofthe pads have been decreasing. Thus, the so-called pad-pitch-narrowinghas also been advancing. In order to cope with a further reduction inthe size and the weight, the form of packages has been changing from aquad flat package (QFP) or a small outline package (SOP) to a chip sizepackage (CSP) or a ball grid array (BGA), which copes easily with anincrease in pins therein and can attain higher density packaging. Aboutthese packages, in recent years, new structure types such as a face-downtype, a stacked type, a flip chip type and a wafer level type have beendeveloped in order to realize high operation-speed or multifunctionalsemiconductor devices.

Flip chip packaging is a connecting technique instead of conventionalwire bonding. Solder bumps are stuck onto pads of a semiconductor chip,and the bumps are used to connect them to lands on a wiring board. Thechip onto which the solder bumps are stuck is positioned on the wiringboard, and then the solder is melted by reflow. Electric and mechanicalconnections are then formed through a self alignment process. In thethus-packaged device, an under filler is filled into a gap between thechip and the wiring board in order to improve various reliabilities. Theunder filler is required to have a high filling ability in order to fillthe material completely into the narrow gap, wherein the solder bumpsare arranged, without generating cavities such as voids.

In order to solve this problem, there has been hitherto adopted a methodof using an encapsulating epoxy resin molding material of a solvent ornon-solvent liquid type which is made mainly of a bisphenol epoxy resin,penetrating the material into the gap between the chip and the wiringboard by use of capillarity, and then curing the material.

However, the liquid type encapsulating epoxy resin molding material isexpensive. Thus, from the viewpoint of a reduction in costs, a newvacuum-manner molding technique using a solid type encapsulating epoxyresin molding material has been developed for an under fill for flipchips. However, the conventional solid type molding material has a lowfilling ability. As a result, it is difficult to encapsulatesemiconductor elements without generating defects such as voids in thepresent circumferences. For example, in the production of anext-generation flip chip type semiconductor device having solder bumpsarrange data fine pitch, at the time of encapsulating it with aconventional solid type encapsulating epoxy resin, the filling thereofinto an under fill portion is unsatisfactorily because of the generationof voids having a somewhat large size of about 0.1 mm in diameter.Hereafter, a higher filling ability will be required in light of atendency that the height and pitch of bumps decrease and further thenumber of the bumps and the chip area increase, following an increase inthe number of inputs and outputs.

For this reason, an encapsulating epoxy resin molding material has beendesired which is excellent in filling ability suitable as an underfiller for flip chip packaging. Furthermore, a flip chip typesemiconductor device has been desired which has solder bumps arranged ata fine pitch, has no molding defects, and is good in reliabilities suchas reflow resistance and humidity resistance.

Incidentally, for semiconductor devices in an up-to-date field, the moldarray package (MAP) molding manner is established instead of lead frameswhich have been conventionally used as inserts, the MAP molding mannerbeing a manner of mounting plural elements on an organic substrate, aceramic substrate or the like, package-molding them with an epoxy resinmolding material, and then cutting and separating the elements. Thismanner has been becoming the main current of molding manners from theviewpoint of a reduction in member costs and an improvement inproductivity. In this case, there has been developed a method calledflip chip packaging, wherein solder balls are fitted to elements insteadof Au lines used as connectors between the elements and wiring and thenthe solder balls are used to connect the elements to lands on a wiringboard, from the viewpoint of high-speed operability and highfunctionalization of the elements. A chip onto which solder balls arestuck is positioned on a wiring board, and then the solder is melted byreflow. Through a self-alignment process, electrical and mechanicalconnections are then formed therein.

However, according to flip chip packaging, the surface of elements andsolder ball portions contact outer air. Therefore, the reliability isremarkably lowered. For this reason, investigations have been made forimproving the reliability, making the size of semiconductors small,making the operating speed thereof high, and improving the productivitythereof by combining the packaging with the above-mentioned MAP moldingmanner.

Problems caused by combining the flip chip packaging with the MAPmolding manner are a warp of a molded substrate, and a warp of packagescut into individual pieces. The substrate warp remarkably causesdifficulties in the step of cutting and separating molded semiconductorsinto individual pieces or at the time of fitting solder bumps.Furthermore, the package warp causes poor connection at the time ofmounting the package on a wiring board since the package is poor inflatness.

In order to solve this problem, a method of filling a liquid resincalled an under filler has been hitherto investigated as a technique forencapsulating the surface of elements and solder ball portions. However,the liquid resin is more expensive than epoxy resin molding material,and easily causes a substrate warp after the curing of the resin isfinished. For this reason, this method does not cope with encapsulationof large-sized substrates for an improvement in productivity. Thus,investigation on the application of epoxy resin molding material, whichis inexpensive and is excellent in dimension stability, thereto has beenstarted.

A new vacuum-manner molding technique using an encapsulating epoxy resinmolding material of a solid type has been developed for an under fillfor a flip chip. However, about conventional solid type moldingmaterial, there is adopted a method of making the amount of the fillerlower than that of epoxy resin molding material for SMD from theviewpoint of an improvement in filling ability. Accordingly, a substratewarp and a package warp are easily generated by a shrinkage in the epoxyresin molding material after the material is cured.

Accordingly, there have been desired: an encapsulating epoxy resinmolding material which keeps filling ability suitable for an underfiller for flip chip packaging and less causes a substrate warp and apackage warp after the substrate is encapsulated by the material; and aflip chip package type semiconductor device which is encapsulated bythis material, has no molding defects such as voids, and is good inreliabilities such as reflow resistance and humidity resistance.

According to a first aspect of the present invention, an encapsulatingepoxy resin molding material which is suitable for encapsulating a flipchip type package type semiconductor device and which has bumps arrangedat a fine pitch and has a large number of inputs and outputs (a largenumber of the bumps) is provided. A flip chip type package typesemiconductor device which has bumps arranged at a fine pitch, has alarge number of inputs and outputs (a large number of the bumps) and isencapsulated by the encapsulating epoxy resin molding material accordingto the present invention is also provided.

According to a second aspect of the present invention, an encapsulatingepoxy resin molding material which causes a decrease in the following:inconveniences in production which are caused by a warp of anencapsulated substrate of a flip chip package type semiconductor device;and a failure in mounting onto a wiring board, the failure being basedon a warp of the package is provided. A flip chip package typesemiconductor device which is encapsulated by the encapsulating epoxyresin molding material according to the present invention and causes adecrease in the following: inconveniences in production which are causedby a warp of an encapsulated substrate; and a failure in mounting onto awiring board, the failure being based on a warp of the package is alsoprovided.

DISCLOSURE OF THE INVENTION

The present invention relates to the following:

1. An encapsulating epoxy resin molding material, comprising (A) anepoxy resin, (B) a curing agent, and (C) an inorganic filler,

wherein the inorganic filler (C) has an average particle size of 12 μmor less and a specific surface area of 3.0 m²/g or more.

2. An encapsulating epoxy resin molding material, comprising (A) anepoxy resin, (B) a curing agent, and (C) an inorganic filler,

wherein the inorganic filler (C) comprises 5% or more by weight of aninorganic filler having a maximum particle size of 63 μm or less andparticle sizes of 20 μm or more.

3. An encapsulating epoxy resin molding material, comprising (A) anepoxy resin, (B) a curing agent, and (C) an inorganic filler,

the inorganic filler (C) having an average particle size of 15 μm orless and a specific surface area of 3.0 to 6.0 m²/g, and the moldingmaterial being used in a semiconductor device having one or more of thefollowing structures (a1) to (d1):

(a1) a structure wherein a bump height of a flip chip is 150 μm or less,

(b1) a structure wherein a bump pitch of the flip chip is 500 μm orless,

(c1) a structure wherein an area of a semiconductor chip is 25 mm² ormore, and

(d1) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 2 mm or less.

4. An encapsulating epoxy resin molding material, comprising (A) anepoxy resin, (B) a curing agent and (C) an inorganic filler, and furthercomprising (D) a coupling agent,

wherein the specific surface area of the inorganic filler (C) is from3.0 to 6.0 m²/g,.

5. An encapsulating epoxy resin molding material, comprising (A) anepoxy resin, (B) a curing agent, and (C) an inorganic filler,

the encapsulating epoxy resin molding material satisfying at least oneof the following conditions: the glass transition temperature based onTMA method is 150° C. or higher; the bending modulus based on JIS-K 6911is 19 GPa or less; and the mold shrinkage ratio based on JIS-K 6911 is0.2% or less.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a sectional view of a flip chip type BGA (of an underfill type) encapsulated by an encapsulating epoxy resin molding material(encapsulating material).

FIG. 2 illustrates a sectional view of a flip chip type BGA (of anover-molded type) encapsulated by an encapsulating epoxy resin moldingmaterial (encapsulating material).

FIG. 3 illustrates a top view (partially perspetive view) when asemiconductor chip 3 is arranged onto a wiring board 1 to interposesolder bumps 2 therebetween.

FIG. 4 illustrate (x) a sectional view and (y) a top view afterover-molding package-encapsulation (MAP molding) of a semiconductordevice (flip chip BGA).

EXPLANATION OF REFERENCE NUMERALS

1: wiring board

2: solder bump

3: semiconductor chip

4: encapsulating material

5: under fill portion

a: bump height

b: bump pitch

c: the area of a semiconductor chip

d: the total thickness of an encapsulating material

11: wiring board

12: solder bump

13: semiconductor chip

14: encapsulating material

PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION

In order to solve the above-mentioned problems, the inventors haverepeated eager investigations so as to find out that the above-mentionedobjects can be attained by a specific encapsulating epoxy resin moldingmaterial for semiconductors which comprises a specific inorganic filleras an essential component, and a semiconductor device encapsulated bythis filler. As a result, the present invention has been made.

(Epoxy Resin)

The epoxy resin (A) used in the present invention is a resin which isordinarily used in encapsulating epoxy resin molding material, and isnot particularly limited. Examples thereof include an epoxidized productof a Novolak resin, which is obtained by condensing or co-condensing aphenol compound such as phenol, cresol, xylenol, resorcin, catechol,bisphenol A or bisphenol F and/or a naphthol compound such asα-naphthol, β-naphthol or dihydroxynaphthalene, and a compound having analdehyde group such as formaldehyde, acetoaldehyde, propionaldehyde,benzaldehyde or salicylaldehyde in the presence of an acidic catalyst,typical examples of the epoxidized product including a phenol Novolakepoxy resin, an o-cresol Novolak epoxy resin and an epoxy resin having atriphenylmethane skeleton, diglycidyl ethers of bisphenol A, bisphenolF, bisphenol S, alkyl-substituted or unsubstituted biphenol or the like,a stylbene epoxy resin, a hydroquinone epoxy resin, a glycidyl esterepoxy resin obtained by reaction of a polybasic acid such as phthalicacid or dimer acid with epichlorohydrin, a glycidylamine epoxy resinobtained by reaction of a polyamine such as diaminodiphenylmethane orisocyanuric acid with epichlorohydrin, an epoxidized product of aco-condensed resin of dicyclopentadiene and a phenol compound, an epoxyresin having a naphthalene ring, an epoxidized product of an aralkylphenol resin such as a phenol/aralkyl resin or a naphthol/aralkyl resin,a trimethylolpropane epoxy resin, a terpene-modified epoxy resin, alinear aliphatic epoxy resin obtained by oxidizing olefin bonds with aperacid such as a peracetic acid, an alicyclic epoxy resin, and asulfur-containing epoxy resin. These may be used alone or in combinationof two or more thereof.

Among these, a biphenyl epoxy resin, a bisphenol F epoxy resin, astylbene epoxy resin and a sulfur-containing epoxy resin are preferredfrom the viewpoint of filling ability and reflow resistance. From theviewpoint of curability, a Novolak epoxy resin is preferred, and fromthe viewpoint of low hygroscopicity, a dicyclopentadiene epoxy resin ispreferred. From the viewpoint of heat resistance and low warpingproperty, a naphthalene epoxy resin and a triphenylmethane epoxy resinare preferred. It is preferred that at least one of these epoxy resinsis contained.

An example of the biphenyl epoxy resin is an epoxy resin represented bythe following general formula (IV); an example of the bisphenol F epoxyresin is an epoxy resin represented by the following general formula(V); an example of the stylbene epoxy resin is an epoxy resinrepresented by the following general formula (VI); and an example of thesulfur-containing epoxy resin is an epoxy resin represented by thefollowing general formula (VII):

wherein R¹ to R⁸, which may be the same or different, are each selectedfrom a hydrogen atom and substituted or unsubstituted monovalenthydrocarbon groups having 1 to 10 carbon atoms, and n represents aninteger of 0 to 3,

wherein R¹ to R⁸, which may be the same or different, are each selectedfrom alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aralkylgroups having 6 to 10 carbon atoms, and n represents an integer of 0 to3,

wherein R¹ to R⁸, which may be the same or different, are each selectedfrom a hydrogen atom and substituted or unsubstituted monovalenthydrocarbon groups having 1 to 5 carbon atoms, and n represents aninteger of 0 to 10,

wherein R¹ to R⁸, which may be the same or different, are each selectedfrom a hydrogen atom, substituted or unsubstituted alkyl groups having 1to 10 carbon atoms, and substituted or unsubstituted alkoxy groupshaving 1 to 10 carbon atoms, and n represents an integer of 0 to 3.

Examples of the biphenyl epoxy resin represented by the general formula(IV) include an epoxy resin made mainly of4,4′-bis(2,3-epoxypropoxy)biphenyl or4,4′-bis(2,3-epoxypropoxy)-3,3′,5,5′-tetramethylbiphenyl; and an epoxyresin obtained by causing epichlorohydrin to react with 4,4′-biphenyl or4,4′-(3,3′,5,5′-tetramethyl)biphenyl. Among these, preferred is an epoxyresin made mainly of4,4′-bis(2,3-epoxypropoxy)-3,3′,5,5′-tetramethylbipheny.

An example of the bisphenol F epoxy resin represented by the generalformula (V) is YSLV-80XY (trade name, manufactured by Nippon SteelChemical Co., Ltd.), which is made mainly of a component wherein R¹, R³,R⁶ and R⁸ are each a methyl group and R², R⁴, R⁵ and R⁷ are each ahydrogen atom, and n is 0, and which is commercially available.

The stylbene epoxy resin represented by the general formula (VI) can beobtained by causing a stylbene phenol compound and epichlorohydrin,which are starting materials, to react with each other in the presenceof a basic material. Examples of this stylbene phenol compound, which isone of the starting materials, include3-t-butyl-4,4′-dihyroxy-3′,5,5′-trimethylstylbene,3-t-butyl-4,4′-dihyroxy-3′,5′,6-trimethylstylbene,4,4′-dihyroxy-3,3′,5,5′-tetramethylstylbene,4,4′-dihyroxy-3,3′-di-t-butyl-5,5′-dimethylstylbene, and4,4′-dihyroxy-3,3′-di-t-butyl-6,6′-dimethylstylbene. Among these,preferred are 3-t-butyl-4,4′-dihyroxy-3′,5,5′-trimethylstylbene, and4,4′-dihyroxy-3,3′,5,5′-tetramethylstylbene. These stylbene phenolcompounds may be used alone or in combination of two or more thereof.

Of the sulfur-containing epoxy resins represented by the general formula(VII), preferred is an epoxy resin wherein R², R³, R⁶ and R⁷ are each ahydrogen atom and R¹, R⁴, R⁵ and R⁸ are each an alkyl group. Morepreferred is an epoxy resin wherein R², R³, R⁶ and R⁷ are each ahydrogen atom, R¹ and R⁸ are each a t-butyl group, and R⁴ and R⁵ areeach a methyl group. Such a compound is YSLV-120TE (manufactured byNippon Steel Chemical Co., Ltd.) or the like as a commercially availableproduct.

These epoxy resins may be used alone or in combination of two or morethereof. The total blended amount thereof is set preferably to 20% ormore by weight, more preferably to 30% or more by weight, even morepreferably to 50% or more by weight of the total of the epoxy resin(s)in order to exhibit performances thereof.

Examples of the Novolak epoxy resin include an epoxy resin representedby the following general formula (VIII):

wherein R is selected from a hydrogen atom and substituted orunsubstituted monovalent hydrocarbon groups having 1 to 10 carbon atoms,and n represents an integer of 0 to 10.

The Novolak epoxy resin represented by the general formula (VIII) caneasily be obtained by causing a Novolak phenol resin to react withepichlorohydrin. R in the general formula (VIII) is preferably an alkylgroup having 1 to 10 carbon atoms, such as a methyl, ethyl, propyl,butyl, isopropyl, or isobutyl group, and an alkoxy group having 1 to 10carbon atoms, such as a methoxy, ethoxy, propoxy or butoxy group. Ahydrogen atom or a methyl group is more preferred. n is preferably aninteger of 0 to 3. Of the Novolak resins represented by the generalformula (VIII), an o-cresol Novolak epoxy resin is preferred.

In the case of using the Novolak epoxy resin, the blended amount thereofis set preferably to 20% or more by weight, more preferably to 30% ormore by weight of the total of the epoxy resin(s) in order to exhibitperformances thereof.

Examples of the dicyclopentadiene epoxy resin include an epoxy resinrepresented by the following general formula (IX)

wherein R¹ and R²are each independently selected from a hydrogen atomand substituted or unsubstituted monovalent hydrocarbon groups having 1to 10 carbon atoms, n represents an integer of 0 to 10 and m representsan integer of 0 to 6.

Examples of R¹ in the formula (IX) include a hydrogen atom, andsubstituted or unsubstituted monovalent hydrocarbon groups having 1 to 5carbon atoms, such as alkyl groups such as methyl, ethyl, propyl, butyl,isopropyl and t-butyl groups, alkenyl groups such as vinyl, allyl andbutenyl groups, halogenated alkyl groups, amino group substituted alkylgroups, and mercapto group substituted alkyl groups. Among these, alkylgroups such as methyl and ethyl groups, and a hydrogen atom arepreferred. A methyl group and a hydrogen atom are more preferred.Examples of R² include a hydrogen atom, and substituted or unsubstitutedmonovalent hydrocarbon groups having 1 to 5 carbon atoms, such as alkylgroups such as methyl, ethyl, propyl, butyl, isopropyl and t-butylgroups, alkenyl groups such as vinyl, allyl and butenyl groups,halogenated alkyl groups, amino group substituted alkyl groups, andmercapto group substituted alkyl groups. Among these, a hydrogen atom ispreferred.

In the case of using the dicyclopentadiene epoxy resin, the blendedamount thereof is set preferably to 20% or more by weight, morepreferably to 30% or more by weight of the total of the epoxy resin(s)in order to exhibit performances thereof.

Examples of the naphthalene epoxy resin include an epoxy resinrepresented by the following general formula (X), and examples of thetriphenylmethane epoxy resin include an epoxy resin represented by thefollowing general formula (XI):

wherein R¹ to R³, which may be the same or different, are each selectedfrom a hydrogen atom and substituted or unsubstituted monovalenthydrocarbon groups having 1 to 12 carbon atoms, p is 1 or 0, 1 and m areeach an integer of 0 to 11 and are each selected to set (1+m) to aninteger of 1 to 11 and set (1+p) to an integer of 1 to 12, and i, j andk represent an integer of 0 to 3, an integer of 0 to 2, and an integerof 0 to 4, respectively.

Examples of the naphthalene epoxy resin represented by the generalformula (X) include a random copolymer comprising one structural unitand structural units the number of which is m at random, an alternatingcopolymer comprising the same alternately, a copolymer comprising thesame regularly, and a block copolymer comprising the same in a blockform. These may be used alone or in combination of two or more thereof.

wherein R is selected from a hydrogen atom and substituted orunsubstituted monovalent hydrocarbon groups having 1 to 10 carbon atoms,and n is an integer of 1 to 10.

These two epoxy resins may be used alone or in combination of the two.The total blended amount thereof is set preferably to 20% or more byweight, more preferably to 30% or more, even more preferably to 50% ormore by weight of the total of the epoxy resin(s) in order to exhibitperformances thereof.

The above-mentioned biphenyl epoxy resin, stylbene epoxy resin,sulfur-containing epoxy resin, Novolak epoxy resin, dicyclopentadieneepoxy resin, naphthalene epoxy resin and triphenylmethane epoxy resinmay be used alone or in combination of two or more thereof. The totalblended amount thereof is set preferably to 50% or more by weight, morepreferably to 60% or more, even more preferably to 80% or more by weightof the total of the epoxy resin(s).

The melting viscosity of the epoxy resin (A) used in the presentinvention is preferably 2 poises or less, preferably 1 poise or less,even more preferably 0.5 poise or less at 150° C. from the viewpoint offilling ability. The melting viscosity indicates viscosity measured withan ICI cone plate viscometer.

(Curing Agent)

The curing agent (B) used in the present invention is an agent which isordinarily used in encapsulating epoxy resin molding material, and isnot particularly limited. Examples thereof include a Novolak phenolresin, which is obtained by condensing or co-condensing a phenolcompound such as phenol, cresol, resorcin, catechol, bisphenol A,bisphenol F, phenylphenol or aminophenol and/or a naphthol compound suchas α-naphthol, β-naphthol or dihydroxynaphthalene, and a compound havingan aldehyde group such as formaldehyde, benzaldehyde or salicylaldehydein the presence of an acidic catalyst, an aralkyl phenol resin, such asa phenol/aralkyl resin or naphthol/aralkyl resin, which is synthesizedfrom a phenol compound and/or a naphthol compound and dimethoxy-p-xyleneor bis(methoxymethyl)biphenyl, a cylopentadiene phenol Novolak resinwhich is synthesized by copolymerizing a phenol compound and/or naphtholcompound and cyclopentadiene, a cyclopentadiene phenol resin such asnaphthol Novolak resin, and a terpene-modified resin. These may be usedalone or in combination of two or more thereof.

Among these, a biphenyl phenol resin is preferred from the viewpoint offlame resistance. From the viewpoint of reflow resistance and curingproperty, an aralkyl phenol resin is preferred. From the viewpoint ofgiving a low hygroscopicity, a dicyclopentadiene phenol resin ispreferred. From the viewpoint of heat resistance, a lowness in theexpansion coefficient and a lowness in the warping property, atriphenylmethane phenol resin is preferred, and from the viewpoint ofcurability, a Novolak phenol resin is preferred. It is preferred that atleast one of these phenol resins is contained.

Examples of the biphenyl phenol resin include a phenol resin representedby the following general formula (XII):

wherein R¹ and R⁹, which may be the same or different, are each selectedfrom a hydrogen atom, alkyl groups having 1 to 10 carbon atoms, such asmethyl, ethyl, propyl, butyl, isopropyl and isobutyl, alkoxy groupshaving 1 to 10 carbon atoms, such as methoxy, ethoxy, propoxy and butoxygroups, aryl groups having 6 to 10 carbon atoms, such as phenyl, tolyland xylyl groups, and aralkyl groups having 6 to 10 carbon atoms, suchas benzyl and phenethyl groups. Among these, a hydrogen atom and amethyl group are preferred. n represents an integer of 0 to 10.

Examples of the biphenyl phenol resin represented by the general formula(XII) include compounds wherein R¹ and R⁹ are each a hydrogen atom.Among these, a condensation product mixture containing 50% or more byweight of a condensation product wherein n is 1 or more is preferredfrom the viewpoint of melting viscosity. One of the compounds isMEH-7851 (trade name, manufactured by Meiwa Plastic Industries, Ltd.),which is commercially available.

In the case of using the biphenyl phenol resin, the blended amountthereof is set preferably to 30% or more by weight, more preferably to50% or more by weight, even more preferably to 60% or more by weight ofthe total of the curing agent(s) in order to exhibit performancesthereof.

Examples of the aralkyl phenol resin include a phenol/aralkyl resin anda naphthol/aralkyl resin. Preferred is a phenol/aralkyl resinrepresented by the following general formula (XIII):

wherein R is selected from a hydrogen and substituted or unsubstitutedmonovalent hydrocarbon groups having 1 to 10 carbon atoms, and nrepresents an integer of 0 to 10. More preferred is a phenol/aralkylresin wherein R in the general formula (XIII) is a hydrogen atom and theaverage of n's is from0 to 8. Specific examples thereof include ap-xylene phenol/aralkyl resin and a m-xylene phenol/aralkyl resin. Inthe case of using these aralkyl phenol resins, the blended amountthereof is set preferably to 30% or more by weight, more preferably to50% or more by weight of the total of the curing agent(s) in order toexhibit performances thereof.

Examples of the dicyclopentadiene phenol resin include a phenol resinrepresented by the following general formula (XIV):

wherein R¹ and R² are each independently selected from a hydrogen atomand substituted or unsubstituted monovalent hydrocarbon groups having 1to 10 carbon atoms, n represents an integer of 0 to 10, and m representsan integer of 0 to 6.

In the case of using the dicyclopentadiene phenol resin, the blendedamount thereof is set preferably to 30% or more by weight, morepreferably to 50% or more by weight of the total of the curing agent(s)in order to exhibit performances thereof.

Examples of the triphenylmethane phenol resin include a phenol resinrepresented by the following general formula (XV):

wherein R is selected from a hydrogen and substituted or unsubstitutedmonovalent hydrocarbon groups having 1 to 10 carbon atoms, and nrepresents an integer of 1 to 10.

In the case of using the triphenylmethane phenol resin, the blendedamount thereof is set preferably to 30% or more by weight, morepreferably to 50% or more by weight of the total of the curing agent(s)in order to exhibit performances thereof.

Examples of the Novolak phenol resin include phenol Novolak resin,cresol Novolak resin, and naphthol Novolak resin. Among these, phenolNovolak resin is preferred. In the case of using the Novolak phenolresin, the blended amount thereof is set preferably to 30% or more byweight, more preferably to 50% or more by weight of the total of thecuring agent(s) in order to exhibit performances thereof.

The above-mentioned biphenyl phenol resin, aralkyl phenol resin,dicyclopentadiene phenol resin, triphenylmethane phenol resin andNovolak phenol resin may be used alone or in combination of two or morethereof. The blended amount thereof is set preferably to 60% or more byweight, more preferably to 80% or more by weight of the total of thecuring agent(s).

The melting viscosity of the curing agent (B) used in the presentinvention is preferably 2 poises or less, more preferably 1 poise orless at 150° C. from the viewpoint of filling ability. The meltingviscosity indicates ICI viscosity.

The equivalent ratio between the epoxy resin (A) and the curing agent(B), that is, the ratio of the number of hydroxyl groups in the curingagent to the number of epoxy groups in the epoxy resin (the number ofhydroxyl groups in the curing agent/the number of epoxy groups in theepoxy resin) is not particularly limited, and is set preferably into therange of 0.5 to 2, more preferably into the range of 0.6 to 1.3 in orderto control unreacted contents of each of them into a low value. Theratio is set even more preferably into the range of 0.8 to 1.2 in orderto obtain an encapsulating epoxy resin molding material excellent inmoldability and reflow resistance.

(Inorganic Filler)

The inorganic filler (C) used in the present invention is a materialincorporated into the encapsulating epoxy resin molding material inorder to decrease the hygroscopicity and the linear expansioncoefficient thereof and improve the thermal conductivity and thestrength thereof. Examples thereof include powder of fused silica,crystal silica, alumina, zircon, calcium silicate, calcium carbonate,potassium titanate, silicon carbide, silicon nitride, aluminum nitride,boron nitride, beryllia, zirconia, zircon, forsterite, steatite, spinel,mullite or titania, beads obtained by making the powder into a sphere,and glass fiber. Examples of the inorganic filler having a flameresistant effect include aluminum hydroxide, magnesium hydroxide, zincborate, and zinc molybdate.

These inorganic fillers may be used alone or in combination of two ormore thereof. Among these, fused silica is preferred from the viewpointof a decrease in the filling ability and the linear expansioncoefficient, and alumina is preferred from the viewpoint of high thermalconductivity. The shape of the inorganic filler is preferably sphericalfrom the viewpoint of filling ability and mold abrasion property.

It is preferred that the inorganic filler (C) used in the invention hasan average particle size of 15 μm or less and a specific surface area of3.0 to 6.0 m²/g in order for the encapsulating epoxy resin moldingmaterial to satisfy filling ability for under filling for a flip chippackage having bumps arrange data fine pitch. The average particle sizeis preferably 10 μm or less, more preferably 8 μm or less. If theparticle size is over 15 μm, the epoxy resin molding material is noteasily injected into the gap between a chip and a wiring board jointedto each other through bumps so that the filling ability lowers. Thespecific surface area is more preferably from 3.5 to 5.5 m²/g, morepreferably from 4.0 to 5.0 m²/g. If the specific surface area is lessthan 3.0 m²/g and more than 6.0 m²/g, voids are easily generated in thegap between a chip and a wiring board jointed to each other throughbumps so that the filling ability lowers.

From the viewpoint of filling ability, coarse particles of the inorganicfiller (C) may be cut with a sieve. At this time, preferably, the amountof the component (C) having a size of 53 μm or more is 0.5% or less byweight. More preferably, the amount of the component (C) having a sizeof 30 μm or more is 0.5% or less by weight. Even more preferably, theamount of the component (C) having a size of 20 μm or more is 0.5% orless by weight.

The blended amount of the inorganic filler (C) is preferably from 60 to95% by weight of the encapsulating epoxy resin molding material from theviewpoint of filling ability and reliability. The amount is morepreferably from 70 to 90% by weight, even more preferably from 75 to 85%by weight. If the amount is less than 60% by weight, the reflowresistance tends to lower. If the amount is more than 95% by weight, thefilling ability tends to lower.

(Coupling Agent)

It is preferred to incorporate a coupling agent into the encapsulatingepoxy resin molding material of the invention in order to make theadhesive property between the resin component and the filler. Ifnecessary, a coupling can be used together as the coupling agent as longas the advantageous effects of the invention can be attained. Thecoupling agent may be a material that is ordinarily used inencapsulating epoxy resin molding material, and is not particularlylimited. Examples thereof include silane compounds having a primary,secondary or tertiary amino group, various silane compounds such asepoxysilane, mercaptosilane, alkylsilane, phenylsilane, ureidosilane andvinylsilane, titanium based compounds, aluminum chelates, andaluminum/zirconium based compounds. These may be used alone or incombination of two or more thereof.

The total blended amount of the coupling agent(s) is preferably from0.037 to 4.75% by weight, more preferably from 0.088 to 2.3% by weightof the encapsulating epoxy resin molding material. If the amount is lessthan 0.037% by weight, the adhesive property to a wiring board tends tolower. If the amount is more than 4.75% by weight, the amount ofvolatile components becomes large so that molding defects about fillingability, such as voids, tend to be easily generated. Moreover, themoldability for packaging tends to lower.

(Silane Coupling Agent Having a Secondary Amino Group)

As the coupling agent, preferred is (D2) a silane coupling agent havinga secondary amino group. If necessary, a different coupling agent may beused together as long as the advantageous effects of the invention canbe attained.

The silane coupling agent (D2),which has a secondary amino group, usedin the invention is not particularly limited if the agent is a silanecompound having in the molecule thereof a secondary amino group.Examples thereof include γ-anilinopropyltrimethoxysilane,γ-anilinopropyltriethoxysilane, γ-anilinopropylmethyldimethoxysilane,γ-anilinopropylmethyldiethoxysilane, γ-anilinopropylethyldiethoxysilane,γ-anilinopropylethyldimethoxysilane, γ-anilinomethyltrimethoxysilane,γ-anilinomethyltriethoxysilane, γ-anilinomethyldimethoxysilane,γ-anilinomethylmethyldiethoxysilane, γ-anilinomethylethyldiethoxysilane,γ-anilinomethylethyldimethoxysilane,N-(p-methoxyphenyl)-γ-aminopropyltrimethoxysilane,N-(p-methoxyphenyl)-γ-aminopropyltriethoxysilane,N-(p-methoxyphenyl)-γ-aminopropylmethyldimethoxysilane,N-(p-methoxyphenyl)-γ-aminopropylmethyldiethoxysilane,N-(p-methoxyphenyl)-γ-aminopropylethyldiethoxysilane,N-(p-methoxyphenyl)-γ-aminopropylethyldimethoxysilane,γ-(N-methyl)aminopropyltrimethoxysilane,γ-(N-ethyl)aminopropyltrimethoxysilane,γ-(N-butyl)aminopropyltrimethoxysilane,γ-(N-benzyl)aminopropyltrimethoxysilane,γ-(N-methyl)aminopropyltriethoxysilane,γ-(N-ethyl)aminopropyltriethoxysilane,γ-(N-butyl)aminopropyltriethoxysilane,γ-(N-benzyl)aminopropyltriethoxysilane,γ-(N-methyl)aminopropylmethyldimethoxysilane,γ-(N-ethyl)aminopropylmethyldimethoxysilane,γ-(N-butyl)aminopropylmethyldimethoxysilane,γ-(N-benzyl)aminopropylmethyldimethoxysilane,N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane,γ-(β-aminoethyl)aminopropyltrimethoxysilane, andN-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane

From the viewpoint of filling ability, an aminosilane coupling agentrepresented by the following general formula (I) is preferred:

wherein R¹ is selected from an hydrogen atom and alkyl groups having 1to 6 carbon atoms, and alkoxy groups having 1 to 2 carbon atoms, R² isselected from alkyl groups having 1 to 6 carbon atoms and a phenylgroup, R³represents a methyl or ethyl group, n represents an integer of1 to 6, and m represents an integer of 1 to 3.

Examples of the aminosilane coupling agent represented by the generalformula (I) include γ-anilinopropyltrimethoxysilane,γ-anilinopropyltriethoxysilane, γ-anilinopropylmethyldimethoxysilane,γ-anilinopropylmethyldiethoxysilane,γ-anilinopropylethyldimethoxysilane,γ-anilinopropylethyldimethoxysilane, γ-anilinomethyltrimethoxysilane,γ-anilinomethyltriethoxysilane, γ-anilinomethylmethyldimethoxysilane,γ-anilinomethylmethyldiethoxysilane, γ-anilinomethylethyldiethoxysilane,γ-anilinomethylethyldimethoxysilane,N-(p-methoxyphenyl)-γ-aminopropyltrimethoxysilane,N-(p-methoxyphenyl)-γ-aminopropyltriethoxysilane,N-(p-methoxyphenyl)-γ-aminopropylmethyldimethoxysilane,N-(p-methoxyphenyl)-γ-aminopropylmethyldiethoxysilane,N-(p-methoxyphenyl)-γ-aminopropylethyldiethoxysilane, andN-(p-methoxyphenyl)-γ-aminopropylethyldimethoxysilane. Particularly,γ-anilinopropyltrimethoxysilane is preferable.

The blended amount of the silane coupling agent (D2),which has asecondary amino group, is preferably from 0.037 to 4.75% by weight, morepreferably from 0.088 to 2.3% by weight of the encapsulating epoxy resinmolding material. If the amount is less than 0.037% by weight, thefluidity thereof lowers so that molding defects about filling ability,such as voids, tend to be easily generated or the adhesive property to awiring board tends to lower. If the amount is more than 4.75% by weight,the amount of volatile components becomes large so that molding defectsabout filling ability, such as voids, tend to be easily generated andfurther the moldability for packaging tends to lower.

The different coupling agent that can be used together with the silanecoupling agent (D2), which has a secondary amino group, is a materialwhich is ordinarily used in encapsulating epoxy resin molding material,and is not particularly limited. Examples thereof include silanecompounds having a primary amino group and/or a tertiary amino group,various silane compounds such as epoxysilane, mercaptosilane,alkylsilane, phenylsilane, ureidosilane and vinylsilane, titanium basedcompounds, aluminum chelates, and aluminum/zirconium based compounds.Examples thereof include silane coupling agents such asvinyltrichlorosilane, vinyltriethoxysilane,vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,γ-glycidoxypropyltrimethoxysialne,γ-glycidoxypropylmethyldimethoxysilane, vinyltriacetoxysilane,γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane,γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane,γ-aminopropylmethyldiethoxysilane,γ-(N,N-dimethyl)aminopropyltrimethoxysilane,γ-(N,N-diethyl)aminopropyltrimethoxysilane,γ-(N,N-dibutyl)aminopropyltrimethoxysilane,γ-(N-methyl)anilinopropyltrimethoxysilane,γ-(N-ethyl)anilinopropyltrimethoxysilane,γ-(N,N-dimethyl)aminopropyltriethoxysilane,γ-(N,N-diethyl)aminopropyltriethoxysilane,γ-(N,N-dibutyl)aminopropyltriethoxysilane,γ-(N-methyl)anilinopropyltriethoxysilane,γ-(N-ethyl)anilinopropyltriethoxysilane,γ-(N,N-dimethyl)aminopropylmethyldimethoxysilane,γ-(N,N-diethyl)aminopropylmethyldimethoxysilane,γ-(N,N-dibutyl)aminopropylmethyldimethoxysilane,γ-(N-methyl)anilinopropylmethyldimethoxysilane,γ-(N-ethyl)anilinopropylmethyldimethoxysilane,N-(trimethoxysilylpropyl)ethylenediamine,N-(dimethoxymethylsilylisopropyl)ethylenediamine,methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane,γ-chloropropyltrimethoxysilane, hexamethyldisilane, andvinyltrimethoxysialne, γ-mercaptopropylmethyldimethoxysilane; titanatecoupling agents such as isopropyltriisostearoyl titanate,isopropyltris(dioctylpyrophosphate)titanate,isopropyltri(N-aminoethyl-aminoethyl)titanate,tetraoctylbis(ditridecylphosphate)titanate,tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl)phosphate titanate,bis(dioctylpyrophosphate)oxyacetate titanate,bis(dioctylpyrophosphate)ethylene titanate, isopropyltrioctanoyltitanate, isopropyldimethacrylisostearoyl titanate,isopropyltridecylbenzenesulfonyl titanate, isopropylisostearoyldiacryltitanate, isopropyltri(dioctylphosphate)titanate,isopropyltricumylphenyl titanate andtetraisopropylbis(dioctylphosphate)titanate. These may be used alone orin combination of two or more thereof.

In the case of using the different coupling agent(s), the blended amountof the silane coupling agent (D2), which has a secondary amino group, isset preferably to 30% ormore by weight, more preferably to 50% or moreby weight of the total of the coupling agents in order to exhibitperformance thereof.

The total blended amount of the coupling agent(s) comprising the silanecoupling agent (D2), which has a secondary amino group, is preferablyfrom 0.037 to 4.75% by weight, more preferably from 0.088 to 2.3% byweight of the encapsulating epoxy resin molding material. If the amountis less than 0.037% by weight, the adhesive property to a wiring boardtends to lower. If the amount is more than 4.75% by weight, the amountof volatile components becomes large so that molding defects aboutfilling ability, such as voids, tend to be easily generated and furtherthe moldability for packaging tends to lower. The blended amount of theabove-mentioned coupling agent(s) is preferably from 0.05 to 5% byweight, more preferably form 0.1 to 2.5% by weight of the inorganicfiller (C). Reasons why the blended amount is specified are the same asdescribed above.

(Coupling Agent Coverage Ratio)

In the case of using the coupling agent in the invention, the coverageratio of the coupling agent for the inorganic filler is set preferablyinto the range of 0. 3 to 1.0, more preferably into the range of 0.4 to0.9, even more preferably into the range of 0.5 to 0.8. If the coverageratio of the coupling agent is larger than 1.0, air bubbles based onvolatile components generated when the material is molded increase sothat voids tend to be easily generated in the resultant thin portion. Ifthe coverage ratio of the coupling agent is smaller than 0.3, theadhesive property between the resin and the filler lowers so that thestrength of the resultant molded product tends to lower.

The coupling agent coverage ratio X of the epoxy resin molding materialis defined as shown in the following equation (xxx):X (%)=S _(c) /S _(f)   (xxx)

S_(c) and S_(f) represent the total minimum covering area of the entirecoupling agent in the epoxy resin molding material, and the totalsurface area of the entire filler therein, respectively, and are definedby the following equations (yyy) and (zzz), respectively:S _(c) =A ₁ ×W ₁ +A ₂ ×W ₂ + . . . +A _(n) ×M _(n) wherein n is thenumber of the used coupling agents,   (yyy), andS _(f) =B ₁ ×W ₁ +B ₂ ×W ₂ + . . . +B ₁ ×W ₁ wherein 1 is the number ofthe used fillers.   (zzz)

A and M represent the minimum covering area and the used amount of eachcoupling agent, respectively, and Band W represent the specific surfacearea and the used amount of each filler.

(Method for Controlling the Coupling Agent Coverage Ratio)

When the minimum covering area of each coupling agent used in the epoxyresin molding material and the specific surface area of each filler usedtherein are already known, the used amounts of the coupling agents andthe fillers which give a target coupling agent coverage ratio can becalculated from the equations (xxx), (yyy) and (zzz).

(Phosphorus Compound)

It is preferred to incorporate (E) a phosphorus compound into thepresent invention from the viewpoint of filling ability and flameresistance. The phosphorus compound (E) used in the invention is notparticularly limited, and examples thereof include phosphorus- andnitrogen-containing compounds such as covered or non-covered redphosphorus and cyclophosphazene, phosphonates such as tricalciumnitrilotrismethylenephosphonate, and dicalciummethane-1-hydroxy-1,1-diphosphonate, phosphine compounds such astriphenylphosphine oxide, 2-(diphenylphosphinyl)hydroquinone,2,2-[(2-(diphenylphosphinyl)-1,4-phenylene]bis(oxymethylene)]bis-oxirane,and tri-n-octylphosphine oxide, ester compounds having a phosphorusatom, and phosphorus- and nitrogen-containing compounds such ascyclophosphazene. These may be used alone or in combination of two ormore thereof. Among these, phosphates and phosphine oxide are preferredfrom the viewpoint of humidity resistant reliability.

Red phosphorus acts as a flame retardant, and is not particularlylimited if the advantageous effects of the present invention can beobtained. Red phosphorus is preferably covered red phosphorus such asred phosphorus covered with a thermosetting resin or red phosphoruscovered with inorganic and organic compounds.

The thermosetting resin used in red phosphorus covered with thethermosetting resin is not particularly limited, and example there ofinclude epoxy resin, phenol resin, melamine resin, urethane resin,cyanate resin, urea-formalin resin, aniline-formalin resin, furan resin,polyamide resin, polyamideimide resin, and polyimide resin. These may beused alone or in combination of two or more thereof. It is allowable touse a monomer or oligomer of these resins to attain covering andpolymerization simultaneously and cover red phosphorus with thethermosetting resin produced by the polymerization, or to set thethermosetting resin after red phosphorus is covered with the resin.Among these, epoxy resin, phenol resin and melamine resin are preferredfrom the viewpoint of compatibility thereof with the base resinincorporated into the encapsulating epoxy resin molding material.

The inorganic compound used in red phosphorus covered with the inorganicand organic compounds is not particularly limited, and examples thereofinclude aluminum hydroxide, magnesium hydroxide, calcium hydroxide,titanium hydroxide, zirconium hydroxide, hydrated zirconium oxide,bismuth hydroxide, barium carbonate, calcium carbonate, zinc oxide,titanium oxide, nickel oxide, and iron oxide. These may be used alone orin combination of two or more thereof. Among these, zirconium hydroxide,hydrated zirconium oxide, aluminum hydroxide and zinc oxide arepreferred, which are excellent in phosphate ion supplementing effect.

The organic compound used in red phosphorus covered with the inorganicand organic compounds is not particularly limited, and examples thereofinclude low molecular weight compounds used for surface treatment, suchas coupling agents and chelating agents, and relatively high molecularweight compounds such as thermoplastic resins and thermosetting resins.These may be used alone or in combination of two or more thereof. Amongthese, thermosetting resins are preferred from the viewpoint of coveringeffect thereof. Epoxy resin, phenol resin and melamine resin are morepreferred from the viewpoint of compatibility thereof with the basematerial incorporated into the encapsulating epoxy resin moldingmaterial.

In the case of covering red phosphorus with the inorganic and organiccompounds, the order of covering-treatments therewith is notparticularly limited. Red phosphorus may be covered with the inorganiccompound and then covered with the organic compound, or may be coveredwith the organic compound and then covered with the inorganic compound.Red phosphorus may be covered with a mixture of the two at a time. Theform of the covering is not particularly limited, and may be a physicaladsorption form, a chemical bond form, or some other form. After thecovering, the inorganic compound and the organic compound may beseparately present, or may be in the state that the two are partially orwholly bonded to each other.

The amounts of the inorganic compound and the organic compound are notparticularly limited if the advantageous effects of the presentinvention can be obtained. The ratio by weight of the inorganic compoundto the organic compound (the inorganic compound/the organic compound) ispreferably from 1/99 to 99/1, more preferably from 10/90 to 95/5, evenmore preferably from 30/70 to 90/10. It is preferred to adjust the usedamounts of the inorganic compound and the organic compound or monomersor oligomers which are starting materials thereof so as to give such aratio by weight.

The method for producing covered red phosphorus such as red phosphoruscovered with a thermosetting resin or red phosphorus covered withinorganic and organic compounds is not particularly limited. There maybe used a known covering method described in, e.g., Japanese PatentApplication Laid-Open No. 62-21704, or Japanese Patent ApplicationLaid-Open No. 52-131695. The thickness of the covering film is notparticularly limited if the advantageous effects of the presentinvention can be obtained. The covering may be even on the surface ofred phosphorus, or uneven thereon.

The particle size of red phosphorus is not particularly limited if theadvantageous effects of the invention can be obtained. The averageparticle size thereof (such a particle size that the cumulative weightratio is set to 50% or more by weight in the particle size distribution)is preferably from 1 to 100 μm, more preferably from 5 to 50 μm. If theaverage particle size is less than 1 μm, the phosphate ion concentrationin the resultant molded product becomes high so that the humidityresistance thereof tends to deteriorate. If the size is more than 100μm, defects based on deformation, short circuits and cutting of wires,and others tend to be easily generated in the case that ahighly-integrated, high-density semiconductor device having a narrow padpitch is used.

The phosphorus- and nitrogen-containing compound acts as a flameretardant, and is not particularly limited if the advantageous effectsof the present invention can be obtained. Examples thereof includecyclic phosphazene compounds containing in their main skeleton thefollowing formula(e) (XXV) and/or (XXVI) as a recurring unit orrecurring units, or compounds containing the following formula(e)(XXVII) and/or (XXVIII) as a recurring unit or recurring units, whereinpositions of the substituents on phosphorus atoms in the phosphazenering are different:

In the formula(e) (XXV) and/or (XXVII), m is an integer of 1 to 10, R¹to R⁴, which may be the same or different, are each selected from alkylgroups having 1 to 12 carbon atoms and aryl groups which may have asubstituent, and A represents an alkylene group having 1 to 4 carbonatoms, or an arylene group. In the formula(e) (XXVII) and/or (XXVIII), nis an integer of 1 to 10, R⁵ to R⁸, which may be the same or different,are each selected from alkyl groups having 1 to 12 carbon atoms and arylgroups which may have a substituent, and A represents an alkylene grouphaving 1 to 4 carbon atoms, or an arylene groups. m R¹'s, mR²'s, mR³'sor, mR⁴'s in the formulae may be the same or different, and n R⁵'s, nR⁶'s, n R⁷'s or R⁸'s therein may be the same or different. In theformulae (XXV) to (XXVIII), the alkyl groups having 1 to 12 carbon atomsor the aryl groups which are represented by R¹ to R⁸ and may have asubstituent are not particularly limited. Examples thereof include alkylgroups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl,sec-butyl and tert-butyl groups, aryl groups such as phenyl, 1-naphthyland 2-naphthyl groups, alkyl-substituted aryl groups such as o-tolyl,m-tolyl, p-tolyl, 2,3-xylyl, 2,4-xylyl, o-cumenyl, m-cumenyl, p-cumenyland mesityl groups, and aryl-substituted alkyl groups such as benzyl andphenethyl groups. Examples of the substituent substituted thereoninclude alkyl, alkoxyl, aryl, hydroxyl, amino, epoxy, vinyl,hydroxyalkyl and alkylamino groups.

Among these, aryl groups are preferred and phenyl and hydroxyphenylgroups are more preferred from the viewpoint of the heat resistance andthe humidity resistance of the epoxy resin molding material. Inparticular, at least one of R¹ to R⁴ is preferably a hydroxyphenylgroup. All of R¹ to R⁸ may be hydroxyphenyl groups. One of R¹ to R⁴ ismore preferably a hydroxyphenyl group. When all of R¹ to R⁸ arehydroxyphenyl groups, the epoxy resin cured product easily becomesbrittle. When all of R¹ to R⁸ are phenyl groups, the heat resistance ofthe epoxy resin cured product lowers easily since the compound is nottaken in the crosslinked structure of the epoxy resin.

The alkylene group having 1 to 4 carbon atoms or arylene group which isrepresented by A in the formulae (XXV) to (XXVIII) is not particularlylimited. Examples thereof include methylene, ethylene, propylene,isopropylene, butylene, isobutylene, phenylene, tolylene, xylylene, andnaphthylene groups. From the viewpoint of the heat resistance and thehumidity resistance of the epoxy resin molding material, an arylenegroup is preferred, and a phenylene group is more preferred.

The cyclic phosphazene compound is a polymer of any one of formulae(XXV) to (XXVIII), a copolymer of the formula (XXV) and the formula(XXVI), or a copolymer of the formula (XXVII) and the formula (XXVIII).In the case of the copolymer, the copolymer may be a random copolymer, ablock copolymer or an alternating copolymer. The copolymerization moleratio thereof, m/n, is not particularly limited, and is preferably from1/0 to 1/4, more preferably from 1/0 to 1/1.5 from the viewpoint of animprovement in the heat resistance and the strength of the epoxy resincured product. The polymerization degree thereof, m+n, is from 1 to 20,preferably from 2 to 8, even more preferably from 3 to 6.

Preferred examples of the cyclic phosphazene compound include a polymerof the following formula (XXIX) and a copolymer of the following formula(XXX):

wherein m is an integer of 0 to 9, and R¹ to R⁴ each independentlyrepresent a hydrogen atom or a hydroxyl groups.

In the formula (XXX), m and n are each an integer of 0 to 9, R¹ to R⁴are each independently selected from hydrogen or a hydroxyl group, andR⁵ to R⁸ are each independently selected from hydrogen or a hydroxylgroup. The cyclic phosphazene compound represented by the formula (XXX)may be a compound wherein recurring units (a), the number of which is m,and recurring units (b), the number of which is n, are alternatelycontained, are contained in a block form, or are contained at random.Preferred is the compound wherein these recurring units are contained atrandom.

Particularly preferred is a compound made mainly of a polymer whereinone of R¹ to R⁴ is a hydroxyl group and m is from 3 to 6 in the formula(XXIX) or a compound made mainly of a copolymer wherein one of R¹ to R⁴is a hydroxyl group, all of R⁵ to R⁸ are hydrogen or one of R⁵ to R⁸ isa hydroxyl group, m/n is from 1/2 to 1/3 and m+n is from 3 to 6 in theformula (XXX). As a commercially available phosphazene compound, SPE-100(trade name, manufactured by Otsuka Chemical Co., Ltd.) can be obtained.

The phosphate is not particularly limited if the phosphate is an estercompound made from phosphoric acid and an alcoholic compound or phenoliccompound. Examples thereof include trimethyl phosphate, triethylphosphate, triphenyl phosphate, tricresyl phosphate, trixylenylphosphate, cresyldiphenyl phosphate, xylenyldiphenyl phosphate,tris(2,6-dimethylphenyl)phosphate, and aromatic condensed phosphates.Among these, an aromatic condensed phosphate represented by thefollowing general formula (II) is preferred from the viewpoint ofhydrolysis resistance thereof:

wherein R's, the number of which is eight, may be the same or different,and each represent an alkylgroup having 1 to 4, and Ar represents anaromatic ring.

Examples of the phosphate of the formula (II) include phosphatesrepresented by the following structural formulae (XVI) to (XX):

The added amount of the phosphate is preferably from 0.2 to 3.0% byweight of all the blended components except the filler, the added amountbeing conversed into the ratio of phosphorus atoms. If the ratio is lessthan 0.2% by weight, the filling ability lowers so that molding defectssuch as voids are easily generated. Moreover, the flame resistant effecttends to lower. If the ratio is more than 3.0% by weight, themoldability and the humidity resistance lower and further when the epoxyresin molding material is molded, the phosphate oozes out to damage theexternal appearance.

The phosphine oxide is preferably a compound represented by thefollowing general formula (III):

wherein R¹, R² and R³, which may be the same or different, eachrepresent a substituted or unsubstituted alkyl group having 1 to 10carbon atoms, an aryl group, an aralkyl group, or a hydrogen atomprovided that the case that all of R¹, R² and R³ are hydrogen atoms isexcluded.

About phosphorus compounds represented by the general formula (I), R¹ toR³ are preferably substituted or unsubstituted aryl groups, and are inparticular preferably phenyl groups from the viewpoint of hydrolysisresistance.

The blended amount of the phosphine oxide is preferably from 0.01 to0.2%, more preferably from 0.02 to 0.1%, even more preferably from 0.03to 0.08% by weight of the encapsulating epoxy resin molding material,the blended amount being converted into the ratio of phosphorus atoms.If the ratio is less than 0.01% by weight, the flame resistance lowers.If the ratio is more than 0.2% by weight, the moldability and thehumidity resistance lower.

(Curing Accelerator)

It is preferred to incorporate (F) a curing accelerator into the presentinvention from the viewpoint of curability. The curing accelerator (F)used in the invention is not particularly limited if the curingaccelerator is a curing accelerator which is ordinarily used inencapsulating epoxy resin molding material. Examples thereof includecycloamidine compounds such as 1,8-diaza-bicyclo(5,4,0)undecene-7,1,5-diaza-bicyclo(4,3,0)nonene and5,6-dibutylamino-1,8-diaza-bicyclo(5,4,0)undecene-7, and compounds whicheach have intermolecular polarization and are obtained by adding, to anyone of these compounds, a compound having a π bond, such as quinonecompounds such as maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone,1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone,2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone,phenyl-1,4-benzoquinone and diazophenylmethane or phenyl resin; tertiaryamines such as benzyldimethylamine, triethanolamine,dimethylaminoethanol and tris(dimethylaminomethyl)phenol, andderivatives thereof; imidazoles such as 2-methylimidazole,2-phenylimidazole and 2-phenyl-4-methylimidazole, and derivativesthereof; organic phosphines such as tributylphosphine,methyldiphenylphosphine, triphenylphosphine,tris(4-methylphenyl)phosphine, diphenylphosphine and phenylphosphine,and phosphorus compounds which each have intermolecular polarization andare obtained by adding to any one of these phosphines a compound havinga n bond such as maleic anhydride, any one of the above-mentionedquinone compounds, diazophenylmethane or phenyl resin; andtetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenyl borate, 2-ethyl-4-methylimidazoletetraphenyl borate and N-methylmorpholine tetraphenyl borate, andderivatives thereof. These may be used alone or in combination of two ormore thereof. In particular, an adduct of an organic phosphine and aquinone compound is preferred from the viewpoint of filling ability andreflow resistance.

The blended amount of the curing accelerator is not particularly limitedif the amount is such an amount that curing accelerating effect can beattained. The amount is preferably from 0.005 to 2% by weight, morepreferably from 0.01 to 0.5% by weight of the encapsulating epoxy resinmolding material. If the amount is less than 0.005% by weight, thecurability in a short time tends to deteriorate. If the amount is morethan 2% by weight, the curing speed is too large so that a good moldedproduct tends not to be easily obtained.

(Flame Retardant)

Various flame retardants may be added to the present invention from theviewpoint of flame resistance. The flame retardants may be flameretardants which are ordinarily used in encapsulating epoxy resinmolding material, and are not particularly limited. Examples thereofinclude brominated epoxy resins such as a diglycidyl etherized productof tetrabromobisphenol A and brominated phenol Novolak epoxy resin,antimony oxide, phosphorus compounds such as red phosphorus and theabove-mentioned phosphates, nitrogen-containing compounds such asmelamine, melaminecyanurate, melamine-modified phenol resin andguanamine-modified phenol resin, phosphorus/nitrogen-containingcompounds such as cyclophosphazene, metal compounds such as zinc oxide,iron oxide, molybdenum oxide, ferrocene, the above-mentioned aluminumhydroxide, magnesium hydroxide, and composite metal hydroxides.

Non-halogen or non-antimony flame retardants are preferred from theviewpoint of environmental problems in recent years and high-temperatureleaving (or standing) property. Among these, phosphates are preferredfrom the viewpoint of filling ability. Composite metal hydroxides arepreferred from the viewpoint of safety and humidity resistance.

A preferred example of the composite metal hydroxides is a compoundrepresented by the following composition formula (XXI):p(M¹aOb)·q(M²cOd)·r(M³cOd)·mH₂O   (XXI)wherein M¹, M² and M³ represent metal elements different from eachother, and a, b, c, d, p, q and m each represent a positive number, andr represents 0 or a positive number.

In particular, more preferred is a compound wherein r is 0 in thecomposition formula (XXI), that is, a compound represented by thefollowing composition formula (XXIa):m(M¹aOb)·n(M²cOd)·lH₂O   (XXIa)wherein M¹ and M² represent metal elements different from each other,and a, b, c, d, m, n and l each represent a positive number.

M¹ and M² in the composition formulae (XXI) and (XXIa) are notparticularly limited if they are metal elements different from eachother. From the viewpoint of flame resistance, it is preferred that M¹and M² are selected not to make them identical with each other, M¹ isselected from metal elements in the third period, alkaline earth metalelements in the group IIA and metal elements in the groups IVB, IIB,VIII, IB, IIIA and IVA, and M² is selected from transition metalelements in the groups IIIB to IIB. It is more preferred that M¹ isselected from magnesium, calcium, aluminum, tin, titanium, iron, cobalt,nickel, copper and zinc, and M² is selected from iron, cobalt, nickel,copper and zinc. From the viewpoint of fluidity, M¹ and M² arepreferably magnesium, and zinc or nickel, respectively, and M¹ and M²are more preferably magnesium and zinc, respectively.

The mole ratio between p, q and r in the composition formula (XXI) isnot particularly limited if the advantageous effects of the inventioncan be obtained. It is preferred that r is 0 and the mole ratio of p toq, p/q, is from 99/1 to 50/50. In other words, it is preferred that themole ratio of m to n, m/n, in the composition formula (XXIa) is from99/1 to 50/50.

The classification of metal elements is performed on the basis of thelong periodic table, wherein typical elements are classified into thesubgroup A and transition elements are classified into the subgroup B,(source: “Kagaku Dai-jiten (Chemistry Large Dictionary) 4”, reduced-sizeversion, the 30^(th) impression printed on Feb. 15, 1987, published byKyoritsu Shuppan Co., Ltd.).

The shape of the composite metal hydroxide is not particularly limited,and is more preferably a polyhedral shape having an appropriatethickness than a planar shape from the viewpoint of fluidity and fillingability. About the composite metal hydroxide, polyhedral crystal is moreeasily obtained than about metal hydroxide.

The blended amount of the composite metal hydroxide is not particularlylimited, and is preferably from 0.5 to 20% by weight, more preferablyfrom 0.7 to 15% by weight, even more preferably from 1.4 to 12% byweight of the encapsulating epoxy resin molding material. If the amountis less than 0.5% by weight, the flame resistance tends to beinsufficient. If the amount is more than 20% by weight, the fillingability and the reflow resistance tend to lower.

(Other Components)

An anionic exchanger can be added to the encapsulating epoxy resinmolding material of the present invention in order to improve thehumidity resistance and the high-temperature leaving property of asemiconductor element such as an IC. The anionic exchanger is notparticularly limited and an anionic exchanger known in the prior art canbe used. Examples thereof include hydrotalcite, and a hydrated oxide ofan element selected from magnesium, aluminum, titanium, zirconium,bismuth and others. These may be used alone or in combination of two ormore thereof. Among these, a hydrotalcite represented by the followingcomposition formula (XXI) is preferred:Mg_(1-x)Al_(x)(OH)₂(CO₃)_(x/2)·mH₂O   (XXI)wherein 0≦X≦0.5, and m is a positive number.

Furthermore, other additives can be incorporated into the encapsulatingepoxy resin molding material of the invention if necessary, examples ofthe additives including releasing agents such as higher aliphatic acids,higher aliphatic acid metal salts, ester waxes, polyolefin waxes,polyethylene and polyethylene oxide, coloring agents such as carbonblack, and stress relaxing agents such as silicone oil and siliconerubber powder.

(Heating Loss Ratio)

The heating loss ratio of the epoxy resin molding material isessentially 0.25% or less by weight, more preferably 0.22% or less byweight, even more preferably 0.20% or less by weight. If the heatingloss ratio is more than 0.25% by weight, air bubbles based on volatilecontents generated when the material is molded increase so that voidsare easily generated in the resultant thin portion.

(Definition of the Heating Loss Ratio)

The weight W₀ of a resin composition added to a heat resistant containerhaving a weight of A is measured. This is allowed to stand still for 1hour in an atmosphere of 200° C. temperature. Thereafter, the totalweight W of the container and the resin composition is measured. At thistime, the heating loss ratio Y is obtained from the following equation:Y=100×(W ₀ −W)/(W ₀ −A)(Method for Controlling the Heating Loss Ratio)

Volatile components generated when the heating loss ratio is measuredare mainly water and alcohols. It is therefore effective to reduce thewater content in the epoxy resin molding material before it is molded,optimize the amount of the coupling agent into a necessary minimumamount, and use a coupling agent which does not generate volatilecomponents easily.

(Physical Properties of the Cured Epoxy Resin Molding Material)

It is preferred to use the encapsulating epoxy resin molding materialsatisfying at least one of the following conditions: the glasstransition temperature based on TMA method is 150° C. or higher; thebending modulus based on JIS-K 6911 is 19 GPa or less; and the moldshrinkage ratio based on JIS-K 6911 is 0.2% or less. The moldingmaterial more preferably satisfies two or more of the above-mentionedconditions, and even more preferably satisfies all of the threeconditions. The glass transition temperature is preferably 160° C. orhigher, more preferably 170° C. or higher from the viewpoint of warp. Ifthe temperature is less than 150° C., the material tends to be largelywarped. The bending modulus is preferably 18.5 GPa or less, morepreferably 18 GPa or less from the viewpoint of warp. If the bendingmodulus is more than 19 GPa, the material tends to be largely warped.The molding shrinkage ratio is preferably 0.18% or less, more preferably0.15% or less from the viewpoint of warp. If the ratio is more than0.2%, the material tends to be largely warped.

(Preparing/Using Methods)

The encapsulating epoxy resin molding material of the present inventioncan be prepared by any method that makes it possible to disperse and mixvarious starting materials homogeneously. A common example of the methodis a method of mixing starting materials sufficiently in given blendedamounts with a mixer or the like, mixing or melt-kneading the materialswith a mixing roll, an extruder, a breaker or crusher, a planetary mixeror the like, cooling the mixture, and optionally defoaming andpulverizing the resultant. If necessary, the molding material may bemade into the form of a tablet having a dimension and weightcorresponding to molding conditions.

The commonest example of the method for encapsulating a semiconductordevice by use of the encapsulating epoxy resin molding material of theinvention is low-pressure transfer molding. Other examples thereofinclude injection molding and compression molding. A dispense manner,casting manner or printing manner may be used. From the viewpoint offilling ability, a molding method which can attain molding in a reducedpressure state is preferred.

The encapsulating epoxy resin molding material of the present inventionwill be further described by way of some embodiments thereof.

First Embodiment

A first embodiment of the encapsulating epoxy resin molding materialaccording to the invention is an encapsulating epoxy resin moldingmaterial comprising (A) an epoxy resin, (B) a curing agent, and (C) aninorganic filler having an average particle size of 12 μm or less and aspecific surface area of 3.0 m²/g or more. In this case, the inorganicfiller (C) preferably satisfies at least one of the followingconditions: the amount of particles having a particle size of 12 μm orless is 50% or more by weight; the amount of particles having a particlesize of 24 μm or less is 70% or more by weight; and the amount ofparticles having a particle size of 32 μm or less is 80% or more byweight; and the amount of particles having a particle size of 48 μm orless is 90% or more by weight. Furthermore, the inorganic filler (C)preferably has an average particle size of 10 μm or less, and preferablyhas a specific surface area of 3.5 to 5.5 m²/g.

The epoxy resin (A), the curing agent (B) and the inorganic filler (C)are preferably selected from the following viewpoints.

In the selection of the epoxy resin (A), an epoxy resin having a meltingviscosity of 2 poises or less at 150° C. is preferably selected, and anepoxy resin having a melting viscosity of 1 poise or less is morepreferably selected. When the ratio of the blended inorganic filler (C)is high, this selection is particularly effective. It is particularlypreferred from the viewpoint of filling ability and reliability to useat least one selected from a biphenyl epoxy resin, a bisphenol F epoxyresin, a stylbene epoxy resin and a sulfur-containing epoxy resin. Inorder to decrease a warp in a flip chip package type package, it ispreferred to use at least one selected from a naphthalene epoxy resinand a triphenylmethane epoxy resin. In order to make the filling abilityand the warp compatible with each other, it is preferred to use thefollowing together: at least one selected from a biphenyl epoxy resin, abisphenol F epoxy resin, a stylbene epoxy resin and a sulfur-containingepoxy resin and at least one selected from a naphthalene epoxy resin anda triphenylmethane epoxy resin.

In the selection of the curing agent (B), a curing agent having amelting viscosity of 2 poises or less at 150° C. is preferably selected,and a curing agent having a melting viscosity of 1 poise or less is morepreferably selected. When the ratio of the blended inorganic filler (C)is high, this selection is particularly effective. Moreover, thisselection is particularly effective when at least one selected fromNovolak epoxy resins is used as the epoxy resin (A) from the viewpointof moldability, when a dicyclopentadiene epoxy resin is used from theviewpoint of a lowness in the hygroscopicity, and when at least oneselected from a naphthalene epoxy resin and a triphenylmethane epoxyresin is used from the viewpoint of heat resistance and a lowness in thewarping property.

In the selection of the inorganic filler (C) which has an averageparticle size of 15 μm or less and a specific surface area of 3.0 to 6.0m²/g, it is preferred to select an inorganic filler having an averageparticle size of 15 μm or less and further having such a size that thefiller can be injected, considering the height and the pitch of bumps ina flip chip package type semiconductor device to be used, the height andthe pitch being within the scope of the present invention. However, if afiller having a smaller size than it needs is selected, the fluidity andthe filling ability lower. In order to avoid this, it is preferred toselect a filler having a specific surface area in the range of 3.0 to6.0 m²/g. In order that both of the average particle size and thespecific surface area can satisfy the above-mentioned ranges, it iseffective to combine two or more commercially available inorganicfillers to prepare a target inorganic filler.

If necessary, coarse particles of the inorganic filler (C) may be cutwith a sieve. The amount of the component (C) having a size of 53 μm ormore is preferably 0.5% or less by weight, the amount of the component(C) having a size of 30 μm or more is more preferably 0.5% or less byweight, and the amount of the component (C) having a size of 20 μm ormore is even more preferably 0.5% or less by weight.

In the selection of the inorganic filler (C), which has an averageparticle size of 12 μm or less and a specific surface area of 3.0 m²/gor more, it is preferred to select an inorganic filler having an averageparticle size of 12 μm or less and further having such a size that thefiller can be injected, considering the height and the pitch of bumps ina flip chip package type semiconductor device to be used. However, if afiller having a smaller size than it needs is selected, a fall in thefluidity is caused. Thus, the selection should be avoided. It iseffective to select an inorganic filler having a specific surface of 3.0m²/g or more and an average particle size which makes it possible thatthe filler is injected and which is as small as possible. In order tosatisfy both of the average particle size and the specific surface areain the above-mentioned ranges, it is effective to combine two or morecommercially available inorganic fillers. If necessary, coarse particlesof the inorganic filler (C) may be cut with a sieve. The amount of thecomponent (C) having a size of 53 μm or more is preferably 0.5% or lessby weight, the amount of the component (C) having a size of 30 μm ormore is more preferably 0.5% or less by weight, and the amount of thecomponent (C) having a size of 20 μm or more is even more preferably0.5% or less by weight.

If desired, any one of (D2) a silane coupling agent having a secondaryamino group, (E) a phosphorus compound, and (F) a curing accelerator maybe added besides the above-mentioned components. The adjustment of thecombination of the respective components and the blended amounts thereofmakes it possible to yield an encapsulating epoxy resin molding materialfor a flip chip package type under fill. The adjustment of thecombination of the respective components and the blended amounts thereofmakes it possible to yield an encapsulating epoxy resin molding materialfor a flip chip package type under fill.

Second Embodiment

A second embodiment of the encapsulating epoxy resin molding materialaccording to the present invention is an encapsulating epoxy resinmolding material comprising (A) an epoxy resin, (B) a curing agent, and5% or more by weight of (C) an inorganic filler having a maximumparticle size of 63 μm or less and particle sizes of 20 μm or more. Inthis case, the average particle size of the inorganic filler (C) ispreferably 10 μm or less. The specific surface area of the inorganicfiller (C) is preferably from 3.5 to 5.5 m²/g. The selection of theepoxy resin (A), the curing agent (B) and the inorganic filler (C) isperformed from the same viewpoints as in the first embodiment.

If desired, any one of (D2) a silane coupling agent having a secondaryamino group, (E) a phosphorus compound, and (F) a curing accelerator maybe added besides the above-mentioned components. The adjustment of thecombination of the respective components and the blended amounts thereofmakes it possible to yield an encapsulating epoxy resin molding materialfor a flip chip package type under fill.

In the case of using an encapsulating epoxy resin of a conventionalsolid type to perform encapsulation in the production of anext-generation flip chip type semiconductor device having bumpsarranged at a fine pitch, the filling thereof into its under fillportion is unsatisfactory because of the generation of relatively largevoids having a diameter of about 0.1 mm. However, the problem can beovercome using, as an encapsulating material, the encapsulating epoxyresin of the present invention, typical examples of which are the firstand second embodiments.

Third Embodiment

A third embodiment of the encapsulating epoxy resin molding materialaccording to the present invention is an encapsulating epoxy resinmolding material comprising, as essential components, (A) an epoxyresin, (B) a curing agent, and (C) an inorganic filler having an averageparticle size of 15 μm or less and a specific surface area of 3.0 to 6.0m²/g. The selection of the epoxy resin (A), the curing agent (B) and theinorganic filler (C) is performed from the same viewpoints as in thefirst embodiment.

If desired, any one of (D2) a silane coupling agent having a secondaryamino group, (E) a phosphorus compound, and (F) a curing accelerator maybe added besides the above-mentioned components. The adjustment of thecombination of the respective components and the blended amounts thereofmakes it possible to yield an encapsulating epoxy resin molding materialfor a flip chip package type under fill. The molding material used, inparticular, in a semiconductor device has one or more of the followingstructures (a1) to (d1):

(a1) a structure wherein a bump height of a flip chip is 150 μm or less,

(b1) a structure wherein a bump pitch of the flip chip is 500 μm orless,

(c1) a structure wherein an area of a semiconductor chip is 25 mm² ormore, and

(d1) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 2 mm or less.

Fourth Embodiment

A fourth embodiment of the encapsulating epoxy resin molding materialaccording to the present invention is an encapsulating epoxy resinmolding material comprising (A) an epoxy resin, (B) a curing agent, (C)an inorganic filler, and (D) a coupling agent, wherein the specificsurface area of the inorganic filler (C) is from 3.0 to 6.0 m²/g. Theselection of the epoxy resin (A), the curing agent (B) and the inorganicfiller (C) is performed from the same viewpoints as in the firstembodiment.

The filler coating ratio of the coupling agent (D) is preferably from0.3 to 1.0. The heating loss ratio after heating at 200° C./hour ispreferably 0.25% or less by weight. If desired, other additives may beadded besides the above-mentioned components. The adjustment of thecombination of the respective components and the blended amounts thereofmakes it possible to yield an encapsulating epoxy resin molding materialfor a flip chip package type under fill.

Fifth Embodiment

A fifth embodiment of the encapsulating epoxy resin molding materialaccording to the present invention is an encapsulating epoxy resinmolding material comprising (A) an epoxy resin, (B) a curing agent, and(C) an inorganic filler, and satisfying at least one of the followingconditions: the glass transition temperature based on TMA method is 150°C. or higher; the bending modulus based on JIS-K 6911 is 19 GPa or less;and the mold shrinkage ratio based on JIS-K 6911 is 0.2% or less. Theselection of the epoxy resin (A), the curing agent (B) and the inorganicfiller (C) is performed from the same viewpoints as in the firstembodiment.

In this case, the molding material is used in a semiconductor devicehaving one or more of the following structures (c1), (d1) and (g1):

(c1) a structure wherein an area of a semiconductor chip is 25 mm² ormore,

(d1) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 2 mm or less,and

(g1) a structure wherein the encapsulating-material molded area based ona package-molding method is 3000 mm² or more. Alternatively, the moldingmaterial is used in a semiconductor device having one or more of thefollowing structures (c2), (d2) and (g2):

(c2) a structure wherein an area of a semiconductor chip is 50 mm² ormore,

(d2) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 1.5 mm orless, and

(g2) a structure wherein the encapsulating-material molded area based ona package-molding method is 5000 mm² or more.

The warp of the semiconductor device obtained by way of the fifthembodiment is 5.0 mm or less, and the warp of the semiconductor deviceis preferably 2.0 mm or less.

In the case of using an encapsulating epoxy resin of a conventionalsolid type to perform encapsulation in the production of anext-generation flip chip type semiconductor device having bumps arrangedata fine pitch, the filling thereof into its under fill portion isunsatisfactory because of the generation of relatively large voidshaving a diameter of about 0.1 mm. However, this problem can be overcomeusing, as an encapsulating material, the encapsulating epoxy resin ofthe present invention, typical examples of which are the 1^(st) to5^(th) embodiments. In other words, the encapsulating epoxy resinmolding material of the invention is used suitably for the production ofa semiconductor device having a given structure, which will be describedlater in the column of semiconductor devices.

According to the fifth embodiment, the encapsulating epoxy resin moldingmaterial has filling ability suitable as an under filler for flip chippackaging and further causes a reduction in a substrate warp and apackage warp after a substrate is subjected to encapsulation with thematerial.

Embodiments 1 of the Semiconductor

Embodiments of the semiconductor device of the present invention aredescribed with reference to FIGS. 1 to 4. The semiconductor device ofthe invention is not limited thereto.

FIG. 1 illustrates a sectional view of a flip chip type BGA of an underfill type, and FIG. 2 illustrates a sectional view of a flip chip typeBGA of an over-molded type. FIG. 3 illustrates a top view (partiallyperspetive view) when a semiconductor chip 3 is arranged over a wiringboard 1 of a flip chip type BGA so as to interpose solder bumps 2therebetween.

A semiconductor device 10 of a flip chip type BGA of an under fill type,illustrated in FIG. 1, is a device obtained by arranging solder bumps 2onto a wiring board 1 so as to have a given bump pitch b, as illustratedin FIG. 3; connecting and fixing a semiconductor chip 3, through thesolder bumps 2 having a bump height a, onto the wiring board 1; andencapsulating an under fill portion 5 formed between the wiring board 1and the semiconductor chip 3 with an encapsulating epoxy resin moldingmaterial (encapsulating material) 4. A semiconductor device 20 of a flipchip type BGA of an over-molded type illustrated in FIG. 2 is producedby the same method as described above except that an under fill portion5 is encapsulated and simultaneously a semiconductor chip 3 isencapsulated so as to cover the whole of the chip 3 in an encapsulatingstep.

At the time of producing the embodiments of the semiconductor device ofthe present invention, it is preferred that the bump height a and thebump pitch b in the semiconductor device, the area c of thesemiconductor chip, and the total thickness d of the encapsulatingmaterial (i.e., the thickness of a package, in which the semiconductorchip is disposed on a mounting substrate) are set as follows.

The height a of the solder bumps 2 is preferably 150 μm or less, morepreferably 100 μm or less, even more preferably 80 μm or less. The pitchb of the solder bumps 2, that is, the interval between the centers ofthe bumps is preferably 500 μm or less, more preferably 400 μm or less,even more preferably 300 μm or less.

The number of the solder bumps 2 is preferably 100 or more, morepreferably 150 or more, even more preferably 200 or more.

The area c of the semiconductor chip 3 is preferably 25 mm² or more,more preferably 50 mm² or more, even more preferably 80 mm² or more.

The total thickness d of the encapsulating material 4 is preferably 2 mmor less, more preferably 1.5 mm or less, even more preferably 1.0 mm orless.

In the case of an under fill type, the total thickness and the height ais the same.

Embodiments 2

FIGS. 4 illustrate a flip chip type BGA wherein bumps 2 are used toconnect and fix a semiconductor chip 3 onto a wiring board 1 and thenthe resultant is encapsulated by an encapsulating epoxy resin moldingmaterial (encapsulating material) 4. FIG. 4(x) is a sectional view(over-molded type) and FIG. 4(y) is a top view (partially perspetiveview).

In the semiconductor device of the invention illustrated in FIGS. 4, thearea c of the semiconductor chip 3 is preferably 25 mm² or more, morepreferably 50 mm² or more, even more preferably 70 mm² or more.

The total thickness d of the encapsulating material 4 is preferably 2 mmor less, more preferably 1.5 mm or less, even more preferably 1.0 mm orless.

The encapsulating-material molded area g based on a package-moldingmethod is preferably 3000 mm² or more, more preferably 5000 mm² or more.

Other Embodiments of the Semiconductor Device

Other embodiments of the semiconductor device of the invention may beflip chip package type semiconductor devices wherein elements such asactive elements such as semiconductor chips, transistors, diodes orthyristors and passive elements such as condensers, resistors, and coilsare mounted on a supporting member or a mounting substrate such as awired tape carrier, a wiring board, or a glass and then the resultant isencapsulated by an encapsulating epoxy resin molding material.

As the encapsulating epoxy resin molding material which constitutes thesemiconductor devices, the encapsulating epoxy resin molding materialaccording to embodiments of the present invention can be used. Forexample, the following is used: an encapsulating epoxy resin moldingmaterial comprising (A) an epoxy resin, (B) a curing agent, and (C) aninorganic filler, wherein the inorganic filler satisfies at least one ofthe following conditions:

(1) the average particle size is 12 μm or less and the specific surfacearea is 3.0 m²/g or more; and

(2) 5% or more by weight of an inorganic filler having a maximumparticle size of 63 μm or less and particle sizes of 20 μm or more iscontained.

If desired, this encapsulating epoxy resin molding material comprises(D2) a silane coupling agent having a secondary amino group and (E) acuring accelerator.

The inorganic filler (C) is preferably an inorganic filler satisfyingthe condition (1) from the viewpoint of filling ability, and ispreferably an inorganic filler satisfying the condition (2) from theviewpoint of an improvement in the burr (flash) resistance. From theviewpoint of the two, a filler satisfying the conditions (1) and (2) ispreferred.

The mounting substrate is not particularly limited, and examples thereofinclude interposer substrates such as an organic substrate, an organicfilm, a ceramic substrate and a glass substrate, a glass substrate forliquid crystal, a substrate for a multi chip module (MCM), and asubstrate for a hybrid IC.

Embodiments of the semiconductor device of the invention preferably hasone or more of the following that are each specified into a given value:(a) a bump height of a flip chip, (b) a bump pitch of the flip chip, (c)an area of a semiconductor chip, (d) a thickness of a package, in whichthe semiconductor chip is disposed on a mounting substrate, (e) a bumpnumber in the flip chip, and (f) a thickness of an air vent when thematerial is molded. Specifically, preferred is a semiconductor devicehaving one or more of the following structures (a1) to (f1):

(a1) a structure wherein a bump height of a flip chip is 150 μm or less,

(b1) a structure wherein a bump pitch of the flip chip is 500 μm orless,

(c1) a structure wherein an area of a semiconductor chip is 25 mm² ormore,

(d1) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 2 mm or less,

(e1) a structure wherein the flip chip has 100 or more bumps, and

(f1) a structure wherein a thickness of an air vent when the material ismolded is 40 μm or less.

More preferred is a semiconductor device having one or more of thefollowing structures (a2) to (f2):

(a2) a structure wherein a bump height of a flip chip is 100 μm or less,

(b2) a structure wherein a bump pitch of the flip chip is 400 μm orless,

(c2) a structure wherein an area of a semiconductor chip is 50 mm² ormore,

(d2) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 1.5 mm orless,

(e2) a structure wherein the number of the bumps in the flip chip is 150or more, and

(f2) a structure wherein a thickness of an air vent when the material ismolded is 30 μm or less.

Even more preferred is a semiconductor device having one or more of thefollowing structures (a3) to (f3):

(a3) a structure wherein a bump height of a flip chip is 150 μm or less,

(b3) a structure wherein a bump pitch of the flip chip is 300 μm orless,

(c3) a structure wherein an area of a semiconductor chip is 80 mm² ormore,

(d3) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 1.0 mm orless,

(e3) a structure wherein the number of the bumps in the flip chip is 200or more, and

(f3) a structure wherein a thickness of an air vent when the material ismolded is 20 μm or less.

The above has described the semiconductor device by way of the preferredembodiments. Particularly preferred are semiconductor devices having thefollowing combinations out of the structures (a) to (f).

From the viewpoint of filling ability, preferred are semiconductordevices having at least one of the structures (a) and (b) Morespecifically, preferred are a semiconductor device having the structures(a1) and (b1), a semiconductor device having the structures (a1) and(d1), a semiconductor device having the structures (a1) and (c1), asemiconductor device having the structures (b) and (d), and asemiconductor device having the structures (b1) and (c1). Furthermore,preferred are a semiconductor device having the structures (a2) and(b2), a semiconductor device having the structures (a2) and (d2), asemiconductor device having the structures (a2) and (c2), asemiconductor device having the structures (b2) and (d2), and asemiconductor device having the structures (b2) and (c2). Furthermore,preferred are a semiconductor device having the structures (a3) and(b3), a semiconductor device having the structures (a3) and (d3), asemiconductor device having the structures (a3) and (c3), asemiconductor device having the structures (b3) and (d3), and asemiconductor device having the structures (b3) and (c3).

Examples of such semiconductor devices include bare chip mountedsemiconductor devices, such as a chip on board (COB) and a chip on glass(COG), which are each obtained by using the encapsulating epoxy resinmolding material of the invention to encapsulate a semiconductor chipconnected to wiring formed on a wiring board or a glass by flip chipbonding; hybrid ICs and multi chip modules (MCMs) which are eachobtained by using the encapsulating epoxy resin molding material of theinvention to encapsulate semiconductor chips, transistors, diodes,thyristors or other active elements connected to wiring formed on awiring board or a glass by flip chip bonding and/or condensers,resistors, coils or other passive elements connected to the wiring inthe same manner; and a ball grid array (BGA), a chip size package (CSP)and a multi chip package (MCP), which are each obtained by mounting asemiconductor chip onto an interposer substrate wherein terminals forconnecting to a mother board are formed, connecting the semiconductorchip to wiring formed on the interposer substrate through bumps, andthen encapsulating the semiconductor chip mounted side of the resultantwith the encapsulating epoxy resin molding material of the invention.These semiconductor devices may be stacked packages wherein two or moreelements are stacked and mounted on a mounting substrate, orpackage-molded type packages wherein two or more elements areencapsulated at a time with the encapsulating epoxy resin moldingmaterial.

Embodiment 2 of the Semiconductor Device

As the encapsulating epoxy resin molding material, an encapsulatingepoxy resin molding material of the present invention is preferred. Thatis, it is preferred to use an encapsulating epoxy resin molding materialcomprising (A) an epoxy resin, (B) a curing agent, and (C) an inorganicfiller, and satisfying at least one of the following conditions: theglass transition temperature based on TMA method is 150° C. or higher;the bending modulus based on JIS-K 6911 is 19 GPa or less; and the moldshrinkage ratio based on JIS-K 6911 is 0.2% or less. It is morepreferred to satisfy two or more of the above-mentioned conditions, andit is even more preferred to satisfy all of the three conditions. Theglass transition temperature is preferably 160° C. or higher, morepreferably 170° C. or higher from the viewpoint of warp. If thetemperature is less than 150° C., the molding material tends to belargely warped. The bending modulus is preferably 18.5 GPa or less, morepreferably 18 GPa or less from the viewpoint of warp. If the bendingmodulus is more than 19 GPa, the molding material tends to be largelywarped. The molding shrinkage ratio is preferably 0.18% or less, morepreferably 0.15% or less from the viewpoint of warp. If the ratio ismore than 0.2%, the molding material tends to be largely warped.

The warp of the semiconductor device encapsulated by the above-mentionedencapsulating epoxy resin molding material is preferably 5.0 mm or less,more preferably 2.0 mm or less, even more preferably 1.5 mm or less. Ifthe warp is more than 0.5 mm in the case of semiconductor devices basedon a package-molding manner, works at the time of cutting and separatingthe molded product into semiconductor individuals or at the time of themounting thereof onto a wiring board tend to be damaged.

The mounting substrate is not particularly limited, and examples thereofinclude interposer substrates such as an organic substrate, an organicfilm, a ceramic substrate and a glass substrate, a glass substrate forliquid crystal, a substrate for a multi chip module (MCM), and asubstrate for a hybrid IC.

Embodiments of the semiconductor device of the invention preferably haveone or more of the following that are each specified into a given value:(a) a bump height of a flip chip, (b) a bump pitch of the flip chip, (c)an area of a semiconductor chip, (d) a thickness of a package, in whichthe semiconductor chip is disposed on a mounting substrate, (e) a bumpnumber in the flip chip, and (g) an encapsulating-material molded areabased on a package-molding method.

Specifically, preferred is a semiconductor device having one or more ofthe following structures (a1) to (g1).

In the invention, the wording “the thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate” means thefollowing in the case of an under fill type: the height of bumpstherein.

(a1) a structure wherein a bump height of a flip chip is 150 μm or less,

(b1) a structure wherein a bump pitch of the flip chip is 500 μm orless,

(c1) a structure wherein an area of a semiconductor chip is 25 mm² ormore,

(d1) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 2 mm or less,

(e1) a structure wherein the number of the bumps in the flip chip is 100or more, and

(g1) a structure wherein the encapsulating-material molded area based ona package-molding method is 3000 mm² or more.

More preferred is a semiconductor device having one or more of thefollowing structures (a2) to (g2):

(a2) a structure wherein a bump height of a flip chip is 100 μm or less,

(b2) a structure wherein a bump pitch of the flip chip is 400 μm orless,

(c2) a structure wherein an area of a semiconductor chip is 50 mm² ormore,

(d2) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 1.5 mm orless,

(e2) a structure wherein the number of the bumps in the flip chip is 150or more, and

(g2) a structure wherein the encapsulating-material molded area based ona package-molding method is 5000 mm² or more.

Even more preferred is a semiconductor device having one or more of thefollowing structures (a3) to (g3):

(a3) a structure wherein a bump height of a flip chip is 80 μm or less,

(b3) a structure wherein a bump pitch of the flip chip is 300 μm orless,

(c3) a structure wherein an area of a semiconductor chip is 80 mm² ormore,

(d3) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 1.0 mm orless,

(e3) a structure wherein the number of the bumps in the flip chip is 200or more, and

(g3) a structure wherein the encapsulating-material molded area based ona package-molding method is 7000 mm² or more.

The above has described the semiconductor device by way of the preferredembodiments. Particularly preferred are semiconductor devices having thefollowing combinations out of the structures (a) to (g).

From the viewpoint of filling ability, preferred are semiconductordevices having at least one of the structures (a) and (b). Morespecifically, preferred are a semiconductor device having the structures(a1) and (b1), a semiconductor device having the structures (a1) and(d1), a semiconductor device having the structures (a1) and (c1), asemiconductor device having the structures (b) and (d), and asemiconductor device having the structures (b1) and (c1). Furthermore,preferred are a semiconductor device having the structures (a2) and(b2), a semiconductor device having the structures (a2) and (d2), asemiconductor device having the structures (a2) and (c2), asemiconductor device having the structures (b2) and (d2), and asemiconductor device having the structures (b2) and (c2). Furthermore,preferred are a semiconductor device having the structures (a3) and(b3), a semiconductor device having the structures (a3) and (d3), asemiconductor device having the structures (a3) and (c3), asemiconductor device having the structures (b3) and (d3), and asemiconductor device having the structures (b3) and (c3).

A semiconductor device having at least one of the structures (c), (d),and (g) is preferred from the viewpoint of the warp thereof. Morespecifically, preferred are a semiconductor having the structures (c1)and (g1), a semiconductor having the structures (c1) and (d1), and asemiconductor having the structures (d1) and (g1). Furthermore,preferred are a semiconductor having the structures (c2) and (g2), asemiconductor having the structures (c2) and (d2), and a semiconductorhaving the structures (d2) and (g2). Furthermore, preferred are asemiconductor having the structures (c3) and (g3),a semiconductor havingthe structures (c3) and (d3), and a semiconductor having the structures(d3) and (g3)

EXAMPLES

The following will describe working examples of the present invention.However, the scope of the invention is not limited to these examples.Each encapsulating epoxy resin molding material and each semiconductordevice were evaluated on the basis of evaluating methods which will bedescribed later unless otherwise specified.

Examples A Example A1 to A7, and Comparative Example A1 to A6

Respective materials are pre-mixed (dry blended) in each blendcomposition shown in Tables 1 to 3, and then the resultant is kneadedwith a biaxial roll having a roll surface temperature of about 80° C.for 10 minutes. Next, the kneaded product is cooled and pulverized toproduce each of encapsulating epoxy resin molding materials A1 to A13 ofExamples A1 to A7 and Comparative Examples A1 to A6. Each of thecompositions in the tables is represented in unit of a part or parts byweight.

(A) Epoxy Resin

The following were used: a biphenyl epoxy resin of EPIKOTE YH-4000H(trade name) manufactured by Japan Epoxy Resins Co., Ltd. (epoxyequivalent: 196, melting point: 106° C.), and a brominated epoxy resinof ESB-400 (trade name) manufactured by Sumitomo Chemical Co., Ltd. (anepi-bis epoxy resin having an epoxy equivalent of 400 and a brominecontent of 49%, diglycidyl-etherized-product of2,2′-bis(4-hydroxy-3,5-dibromophenyl)propane, modified withepichlorohydrin).

(B) Curing Agent

As curing agents (B), the following were used: aphenol/benzaldehyde/xylylenedimethoxide polycondensed productrepresented by the following structural formula (XXII) and having ahydroxyl equivalent of 156 and a softening point of 73° C. (trade name:HE510-05, manufactured by Sumikin Chemical Co.); and aphenol/hydroxybenzaldehyde resin represented by the following structuralformula (XXIII) and having a hydroxyl equivalent of 100 and a softeningpoint of 83° C. (trade name: MEH-7500-3S, manufactured by Meiwa PlasticIndustries, Ltd.):

wherein n represents an integer of 0 to 8,

wherein n represents an integer of 0 to 8.

Thirteen kinds of the produced molding materials were each molded usinga transfer molding machine under the following conditions: a moldtemperature of 180° C., a molding pressure of 6.9 MPa, and a curing timeof 90 seconds. The resultants were each evaluated through spiral flowand gel time tests.

[Production of semiconductor devices A1 (flip chip BGAs)]

Next, the encapsulating epoxy resin molding materials A1 to A13 wereused to produce semiconductor devices of Examples A1 to A7 andComparative Examples A1 to A6. Encapsulation with each of theencapsulating epoxy resin molding materials was performed by using atransfer molding machine to mold the material under conditions of amolding temperature of 180° C., a molding pressure of 6.9 MPa and acuring time of 90 seconds and then curing the molded material at 180° C.for 5 hours.

Examples A1 to A7 (Table 2)

A fine wiring pattern was formed on an insulated base (trade name:E-679, a glass cloth-epoxy resin laminated plate, manufactured byHitachi Chemical Co., Ltd.), and then an insulated protecting resin(trade name: PSR 4000 AUS5, manufactured by Taiyo Ink Mfg. Co., Ltd.)was applied onto surfaces of the resultant except gold-plated terminalson a semiconductor element mounting side surface thereof andoutside-connecting terminals on the opposite side surface, so as to forma semiconductor mounting substrate of length 22 mm×width 14 mm×thickness0.3 mm. The substrate was dried at 120° C. for 2 hours, and then asemiconductor element of length 9 mm×width 8 mm×thickness 0.4 mm (area:72 mm²), to which 160 bumps having a bump diameter of 145 μm and a bumppitch of 200 μm were fitted, was mounted on the substrate by IR reflowtreatment at 260° C. for 10 seconds. The bump height after the mountingwas 100 μm. Next, the encapsulating epoxy resin molding materials A1 toA7 were each used and molded into a size of length 22 mm×width 14mm×thickness 0.7 mm on the semiconductor element mounted surface byvacuum transfer molding under the above-mentioned conditions. In thisway, flip chip BGA devices of Examples A1 to A7 were each produced.

Comparative Examples A1 to A6 (Table 3)

Semiconductor devices of Comparative Examples A1 to A6 were produced inthe same way as in Examples A1 to A7 except that the encapsulating epoxyresin molding materials A8 to A13 were used.

[Production of Semiconductor Devices A2 (Flip Chip BGAs)]

Next, the encapsulating epoxy resin molding materials A1 to A13 wereused to produce semiconductor devices of Examples A1 to A7 andComparative Examples A1 to A6. Encapsulation with each of theencapsulating epoxy resin molding materials was performed by using atransfer molding machine to mold the material under conditions of amolding temperature of 180° C., a molding pressure of 6.9 MPa and acuring time of 90 seconds and then curing the molded material at 180° C.for 5 hours.

Examples A1 to A7 (Table 2)

A fine wiring pattern was formed on an insulated base (trade name:E-679, a glass cloth-epoxy resin laminated plate, manufactured byHitachi Chemical Co., Ltd.), and then an insulated protecting resin(trade name: PSR 4000 AUS5, manufactured by Taiyo Ink Mfg. Co., Ltd.)was applied onto surfaces of the resultant except gold-plated terminalson a semiconductor element mounting side surface thereof andoutside-connecting terminals on the opposite side surface, so as to forma semiconductor mounting substrate of length 22 mm×width 14 mm×thickness0.3 mm. The substrate was dried at 120° C. for 2 hours, and then asemiconductor element of length 6 mm×width 5 mm×thickness 0.4 mm (area:30 mm²), to which 120 bumps having a bump diameter of 300 μm and a bumppitch of 490 μm were fitted, was mounted on the substrate by IR reflowtreatment at 260° C. for 10 seconds. The bump height after the mountingwas 260 μm. Next, the encapsulating epoxy resin molding materials A1 toA7 were each used and molded into a size of length 22 mm×width 14mm×thickness 1.2 mm on the semiconductor element mounted surface byvacuum transfer molding under the above-mentioned conditions. In thisway, flip chip BGA devices of Examples A1 to A7 were each produced.

Comparative Examples A1 to A6 (Table 3)

Semiconductor devices of Comparative Examples A1 to A6 were produced inthe same way as in Examples A1 to A7 except that the encapsulating epoxyresin molding materials A8 to A13 were used.

[Production of Semiconductor Devices A3 (Flip Chip BGAs)]

Next, the encapsulating epoxy resin molding materials A1 to A13 wereused to produce semiconductor devices of Examples A1 to A7 andComparative Examples A1 to A6. Encapsulation with each of theencapsulating epoxy resin molding materials was performed by using atransfer molding machine to mold the material under conditions of amolding temperature of 180° C., a molding pressure of 6.9 MPa and acuring time of 90 seconds and then curing the molded material at 180° C.for 5 hours.

Examples A1 to A7 (Table 2)

A fine wiring pattern was formed on an insulated base (trade name:E-679, a glass cloth-epoxy resin laminated plate, manufactured byHitachi Chemical Co., Ltd.), and then an insulated protecting resin(trade name: PSR 4000 AUS5, manufactured by Taiyo Ink Mfg. Co., Ltd.)was applied onto surfaces of the resultant except gold-plated terminalson a semiconductor element mounting side surface thereof andoutside-connecting terminals on the opposite side surface, so as to forma semiconductor mounting substrate of length 22 mm×width 14 mm×thickness0.3 mm. The substrate was dried at 120° C. for 2 hours, and then asemiconductor element of length 5 mm×width 4 mm×thickness 0.4 mm (area:20 mm²), to which 40 bumps having a bump diameter of 390 μm and a bumppitch of 700 μm were fitted, was mounted on the substrate by IR reflowtreatment at 260° C. for 10 seconds. The bump height after the mountingwas 350 μm. Next, the encapsulating epoxy resin molding materials A1 toA7 were each used and molded into a size of length 22 mm×width 14mm×thickness 2.5 mm on the semiconductor element mounted surface byvacuum transfer molding under the above-mentioned conditions. In thisway, flip chip BGA devices of Examples 1 to 7 were each produced.

Comparative Examples A1 to A6 (Table 3)

Semiconductor devices of Comparative Examples A1 to A6 were produced inthe same way as in Examples Al to A7 except that the encapsulating epoxyresin molding materials A8 to A13 were used.

The produced semiconductor devices of Examples A1 to A7 and ComparativeExamples A1 to A6 were evaluated through the following tests. Theevaluation results are shown in Tables 2 and 3. TABLE 1 Items Filler AFiller B Filler C Filler D Filler E Filler F Filler G Particle size  ˜1μm 11 11 27 27 10 10 11 distribution  ˜2 μm 20 20 38 42 20 21 25(cumulative weight  ˜4 μm 30 30 45 54 29 31 41 percentage)  ˜6 μm 37 3650 63 34 37 52 ˜12 μm 50 53 73 86 45 48 82 ˜24 μm 71 75 87 96 61 68 100˜32 μm 81 83 93 100 72 80 100 ˜48 μm 95 96 98 100 86 94 100 ˜64 μm 100100 100 100 92 97 100 ˜96 μm 100 100 100 100 98 100 100 Average particlesize μm 12 11 6 3 18 15 6 Specific surface area m²/g 3.5 3.3 4.0 3.5 3.53.8 2.7 Maximum particle μm 63 53 53 30 105 75 30 Amount of the fillerwt. % 33 30 15 5 43 37 4 of 20 μm or more in size

TABLE 2 Items Example 1 Example 2 Example 3 Example 4 Example 5 Example6 Example 7 encapsulating epoxy resin molding 1 2 3 4 5 6 7 materials AEpoxy resin YX-4000H 85 85 85 85 85 85 85 *1 15 15 15 15 15 15 15 Curingagent Structural 75 75 75 75 — — — formula (XXII) Structural — — — — 5050 50 formula (XXIII) Curing accelerator *2 3.5 3.5 3.5 3.5 2.5 2.5 2.5Coupling agent *3 5 5 5 5 5 5 5 Antimony trioxide Sb₂O₃ 5 5 5 5 5 5 5Releasing agent Carnauba wax 2 2 2 2 2 2 2 Coloring agent Carbon black 33 3 3 3 3 3 Filler A 1850 — — — — — — B — 1850 — — 1320 — — C — — 1850 —— 1320 — D — — — 1400 — — 1179 E — — — — — — — F — — — — — — — G — — — —— — — Spiral flow cm 105 115 95 100 160 145 130 Gel time sec 38 43 42 4550 50 52 Burr — Good Good Good Good Good Good Good Amount ofSemiconductor 0/20 0/20 0/20 0/20 0/20 0/20 0/20 generated voids device1 Semiconductor 0/20 0/20 0/20 0/20 0/20 0/20 0/20 device 2Semiconductor 0/20 0/20 0/20 0/20 0/20 0/20 0/20 device 3*1: An etherized product of 2,2′-bis(4-hydroxy-3,5-dibromophenyl)propanewith epichlorohydrin*2: Adduct of triphenylphosphine and benzoquinone*3: γ-Glycidoxypropyltrimethoxysilane

TABLE 3 Comparative Comparative Comparative Comparative ComparativeComparative Items Example 1 Example 2 Example 3 Example 4 Example 5Example 6 Encapsulating epoxy resin moulding 8 9 10 11 12 13 material AEpoxy resin YX-4000H 85 85 85 85 85 85 *1 15 15 15 15 15 15 Curing agentStructural 75 75 75 — — — formula (XXII) Structural — — — 50 50 50formula (XXIII) Curing accelerator *2 3.5 3.5 3.5 2.5 2.5 2.5 Couplingagent *3 5 5 5 5 5 5 Antimony trioxide Sb₂O₃ 5 5 5 5 5 5 Releasing agentCarnauba wax 2 2 2 2 2 2 Coloring agent Carbon black 3 3 3 3 3 3 FillerA — — — — — — B — — — — — — C — — — — — — D 1850 — — 1320 — — E F — 1850— — 1320 — G — — 1400 — — 1179 Spiral flow cm 95 100 75 150 160 105 Geltime sec 37 38 42 49 50 50 Burr — Good Good NG Good Good NG Amount ofSemiconductor 20/20 10/20  15/20  20/20 8/20 11/20  generated voidsdevice 1 Semiconductor 15/20 0/20 0/20 13/20 0/20 0/20 device 2Semiconductor  0/20 0/20 0/20  0/20 0/20 0/20 device 3*1: An etherized product of 2,2′-bis(4-hydroxy-3,5-dibromophenyl)propanewith epichlorohydrin*2: Adduct of triphenylphosphine and benzoquinone*3: γ-Glycidoxypropyltrimethoxysilane[Evaluating Methods](1) Spiral Flow (Index of Fluidity)

A spiral flow measuring mold according to EMMI-1-66 was used to mold amaterial and then the flowing distance thereof was obtained.

(2) Gel Time

A curelastometer manufactured by JSR was used to measure the time (sec.)up to a rise of the torque curve of 3 g of a sample at a temperature of180° C.

(3) Amount of Generated Voids

An ultrasonic inquiry video system (HYE-HOCUS model, manufactured byHitachi Construction Machinery Co., Ltd.) was used to observe the insideof semiconductor devices, thereby observing whether voids having adiameter of 0.1 mm or more were generated or not. An evaluation was madeon the basis of the ratio of the number of semiconductor devices whereinthe voids were generated to the number of the semiconductor devicestested.

(4) Burr

A mold having a slit of 10 μm thickness was used to mold a material froma pot. The length of a burr which flowed in the slit was measured with avernier micrometer. If the length of the burr in the slit was less than10 μm, the material was judged good. If the length was 10 μm or more,the material was judged no good.

The encapsulating epoxy resin molding material of the present inventionfor flip chip packaging has a high filling ability required for an underfiller and gives only a small amount of molding defects such as voids.Thus, the industrial value thereof is large.

Examples B

[Production of Encapsulating Epoxy Resin Molding Materials]

Components described below were blended so that the amount of each ofthe components would be a part or parts by weight shown in Table 4 or 5,and then the resultant was roll-kneaded at a kneading temperature of 80°C. for a kneading time of 10 minutes. In this way, encapsulating epoxyresin molding materials B1 to B19 were produced.

(Epoxy Resins)

As epoxy resins, the following were used: a biphenyl epoxy resin havingan epoxy equivalent of 196 and a melting point of 106° C. (trade name:EPIKOTE YX-4000.H, manufactured by Japan Epoxy Resins Co., Ltd.); abisphenol F epoxy resin having an epoxy equivalent of 186 and a meltingpoint of 75° C. (trade name: YSLV-80XY, manufactured by Nippon SteelChemical Co., Ltd.); a stylbene epoxy resin having an epoxy equivalentof 210 and a melting point of 120° C. (trade name: ESLV-210,manufactured by Sumitomo Chemical Co., Ltd.); a sulfur-containing epoxyresin having an epoxy equivalent of 245 and a melting point of 110° C.(trade name: YSLV-120TE, manufactured by Nippon Steel Chemical Co.,Ltd.); a triphenolmethane epoxy resin 1 having an epoxy equivalent of170, a softening point of 60° C., and a melt viscosity of 2.4 poises at150° C. (trade name: EPIKOTE E1032H, manufactured by Japan Epoxy ResinsCo., Ltd.); a triphenolmethane epoxy resin 2 having an epoxy equivalentof 170, a softening point of 70° C., and a melt viscosity of 3.1 poisesat 150° C. (trade name: EPIKOTE E1032H, manufactured by Japan EpoxyResins Co., Ltd.); and an o-cresol Novolak epoxy resin having an epoxyequivalent of 195 and a melting point of 65° C. (trade name: ESCN-190,manufactured by Sumitomo Chemical Co., Ltd.).

(Curing Agents)

As curing agents, the following were used: a phenol/aralkyl resin havinga softening point of 70° C. and a hydroxyl equivalent of 175 (tradename:Milex (transliteration) XL-225, manufactured by Mitsui Chemicals, Inc.);a biphenyl phenol resin having a softening point of 80° C. and ahydroxyl equivalent of 199 (trade name: MEH-7851, manufactured by MeiwaPlastic Industries, Ltd.); a triphenolmethane phenol resin 1 having asoftening point of 83° C., a hydroxyl equivalent of 103, and a meltviscosity of 1.3 poises at 150° C. (trade name: MEH-7500-3S,manufactured by Meiwa Plastic Industries, Ltd.); a triphenolmethanephenol resin 2 having a softening point of 101° C., a hydroxylequivalent of 101, and a melt viscosity of 3.0 poises at 150° C. (tradename: MEH-7500-SS, manufactured by Meiwa Plastic Industries, Ltd.) and aphenol Novolak resin having a softening point of 80° C. and a hydroxylequivalent of 106 (trade name: H-1, manufactured by Meiwa PlasticIndustries, Ltd.).

(Curing Accelerator)

As an accelerator, an adduct of triphenylphosphine and p-benzoquinone(curing accelerator) was used. As coupling agents, the following wereused: a silane coupling agent containing a secondary amino group(γ-anilinopropyltrimethoxysilane (anilinosilane)), andγ-glycidoxypropyltrimethoxysilane (epoxysilane).

(Flame Retardants)

As flame retardants, the following were used: an aromatic condensedphosphate (trade name: PX-200, manufactured by Daihachi ChemicalIndustry Co., Ltd.); triphenylphosphine oxide, a composite metalhydroxide, Echomag Z-10 manufactured by Tateho Chemical Industries Co.,Ltd.), antimony trioxide; and a bisphenol A brominated epoxy resinhaving an epoxy equivalent of 375, a softening point of 80° C. and abromine content of 48% by weight (trade name: ESB-400T, manufactured bySumitomo Chemical Co., Ltd.).

(Inorganic Fillers)

As inorganic fillers, the following were used: a spherical fused silica1 having an average of 6.7 μm and a specific surface area of 3.0 m²/g; aspherical fused silica 2 having an average of 8.8 μm and a specificsurface area of 4.6 m²/g; a spherical fused silica 3 having an averageof 12.5 μm and a specific surface area of 3.2 m²/g; a spherical fusedsilica 4 having an average of 6.0 μm and a specific surface area of 2.7m²/g; a spherical fused silica 5 having an average of 17 μm and aspecific surface area of 3.8 m²/g; and a spherical fused silica 6 havingan average of 0.8 μm and a specific surface area of 6.3 m²/g.

(Other Additives)

As other additives, carnauba wax (manufactured by Clariant Co.) andcarbon black (trade name: MA-100, manufactured by Mitsubishi ChemicalCorp.) were used. TABLE 4 (Formulation compositions 1 of encapsulatingepoxy resin molding material) Encapsulating epoxy resin moldingmaterials B for Examples Blended components 1 2 3 4 5 6 7 8 9 10Biphenyl epoxy resin — — — — — — — — — 85 Bisphenol F epoxy resin 10 1010 10 10 10 10 10 10 — Stylbene epoxy resin — — — — — — — — — —Sulfur-containing epoxy resin — — — — — — — — — — Triphenolmethane epoxyresin 1 75 75 75 75 75 75 — 75 75 — Triphenolmethane epoxy resin 2 — — —— — — 75 — — — o-Cresol Novolak epoxy resin — — — — — — — — — —Brominated epoxy resin 15 15 15 15 15 15 15 15 15 15 Phenol/aralkylresin — — — — — — — — — — Biphenyl phenol resin — — — — — — — — — —Triphenolmethane phenol resin 55 55 55 55 55 55 55 — 55 49Triphenolmethane phenol resin 2 — — — — — — — 55 — — Phenol Novolakresin — — — — — — — — — — Curing accelerator 2.0 2.0 2.0 2.0 2.0 2.0 2.02.0 2.0 3.0 Aromatic condensed phosphate — — — — — — — — — —Triphenylphosphine oxide — — — — — — — — — — Composite metal hydroxide —— — — — — — — — — Antimony trioxide 15 15 15 15 15 15 15 15 15 15Anilinosilane 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 — 4.5 Epoxysilane — — — —— — — — 4.5 — Spherical fused silica 1 868 — — — — — — — — — Sphericalfused silica 2 — 868 — — — — 868 868 868 933 Spherical fused silica 3 —— 868 — — — — — — — Spherical fused silica 4 — — — 868 — — — — — —Spherical fused silica 5 — — — — 868 — — — — — Spherical fused silica 6— — — — — 868 — — — — Carnauba wax 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.02.0 Carbon black 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Inorganicfiller amount 83 83 83 83 83 83 83 83 83 84 (% by weight)

TABLE 5 (Formulation compositions 2 of encapsulating epoxy resin moldingmaterial) Encapsulating epoxy resin molding materials B for ExamplesBlended components 11 12 13 14 15 16 17 18 19 Biphenyl epoxy resin — — —85 — — — — — Bisphenol F epoxy resin 85 — — — — 100 10 10 10 Stylbeneepoxy resin — 85 — — — — — — — Sulfur-containing epoxy resin — — 85 — —— — — — Triphenolmethane epoxy resin 1 — — — — — — 90 90 90Triphenolmethane epoxy resin 2 — — — — — — — — — o-Cresol Novolak epoxyresin — — — — 85 — — — — Brominated epoxy resin 15 15 15 15 15 — — — —Phenol/aralkyl resin — — — 83 — — — — — Biphenyl phenol resin — — — — —107 — — — Triphenolmethane phenol resin 51 46 40 — — — 60 60 60Triphenolmethane phenol resin 2 — — — — — — — — — Phenol Novolak resin —— — — 50 — — — — Curing accelerator 3.5 3.5 3.5 3.5 2.0 3.5 3.0 3.0 3.0Aromatic condensed phosphate — — — — — — 35 — — Triphenylphosphine oxide— — — — — — — 35 — Composite metal hydroxide — — — — — — — — 150Antimony trioxide 15 15 15 15 15 15 15 15 15 Anilinosilane 4.5 4.5 4.54.5 4.5 4.5 4.5 4.5 4.5 Epoxysilane — — — — — — — — — Spherical fusedsilica 1 — — — — — — — — — Spherical fused silica 2 951 922 890 1121 6131756 1076 1076 757 Spherical fused silica 3 — — — — — — — — — Sphericalfused silica 4 — — — — — — — — — Spherical fused silica 5 — — — — — — —— — Spherical fused silica 6 — — — — — — — — — Carnauba wax 2.0 2.0 2.02.0 2.0 2.0 2.0 2.0 2.0 Carbon black 3.5 3.5 3.5 3.5 3.5 3.5 3.0 3.0 3.0Inorganic filler amount 84 84 84 84 78 88 83 83 83 (% by weight)

TABLE 6 (Encapsulating epoxy resin molding material properties 1)Encapsulating epoxy resin molding materials B for Examples Properties 12 3 4 5 6 7 8 9 10 Spiral flow (cm) 171 175 174 100 175 68 113 107 166232 Disc flow 121 130 127 76 127 56 88 81 102 125 Hardness at hot time77 77 78 77 78 76 82 83 76 82 (Shore D) UL-94 test V-0 V-0 V-0 V-0 V-0V-0 V-0 V-0 V-0 V-0

TABLE 7 (Encapsulating epoxy resin molding material properties 2)Encapsulating epoxy resin molding materials B for Examples Properties 1112 13 14 15 16 17 18 19 Spiral flow (cm) 237 229 225 206 145 118 180 178117 Disc flow 127 115 113 110 100 95 133 132 92 Hardness at hot time 8083 79 73 83 75 70 71 78 (Shore D) UL-94 test V-0 V-0 V-0 V-0 V-0 V-0 V-0V-0 V-0[Production of Semiconductor Devices B1 (Flip Chip BGAs)]

Next, the encapsulating epoxy resin molding materials B1 to B19 wereused to produce semiconductor devices of Examples B1 to B16 andComparative Examples B1 to B3. Encapsulation with each of theencapsulating epoxy resin molding materials was performed by using atransfer molding machine to mold the material under conditions of a moldtemperature of 165° C., a molding pressure of 9.8 MPa, a vacuum degreeof 530 Pa, and a curing time of 90 seconds and then curing the moldedmaterial at 165° C. for 5 hours.

Examples B1 to B16 (Tables 8 and 9)

A fine wiring pattern was formed on an insulated base (trade name:E-679, a glass cloth-epoxy resin laminated plate, manufactured byHitachi Chemical Co., Ltd.), and then an insulated protecting resin(trade name: PSR 4000 AUS5, manufactured by Taiyo Ink Mfg. Co., Ltd.)was applied onto surfaces of the resultant except gold-plated terminalson a semiconductor element mounting side surface thereof andoutside-connecting terminals on the opposite side surface, so as to forma semiconductor mounting substrate of length 40 mm×width 40 mm×thickness1.3 mm. The substrate was dried at 120° C. for 2 hours, and then asemiconductor element of length 9 mm×width 8 mm×thickness 0.4 mm (area:72 mm²), which had a bump diameter of 145 μm and a bump pitch of 200 μm,was mounted on the substrate by IR reflow treatment at 260° C. for 10seconds. The bump height after the mounting was 100 μm. Next, theencapsulating epoxy resin molding materials B1 to B3 and B7 to B19 wereeach used and molded into a size of length 12 mm×width 12 mm×thickness0.7 mm on the semiconductor element mounted surface by vacuum transfermolding under the above-mentioned conditions. In this way, flip chip BGAdevices of Examples B1 to B16 were each produced.

Comparative Examples B1 to B3 (Table 12)

Semiconductor devices of Comparative Examples B1 to B3 were produced inthe same way as in Examples B1 to B16 except that the encapsulatingepoxy resin molding materials B4 to B6 were used.

[Production of Semiconductor Devices B2 (Flip Chip BGAs)]

Next, the encapsulating epoxy resin molding materials B1 to B19 wereused to produce semiconductor devices of Examples B17 to B32 andComparative Examples B4 to B6. Encapsulation with each of theencapsulating epoxy resin molding materials was performed by using atransfer molding machine to mold the material under conditions of a moldtemperature of 165° C., a molding pressure of 9.8 MPa, a vacuum degreeof 530 Pa, and a curing time of 90 seconds and then curing the moldedmaterial at 180° C. for 5 hours.

Examples B17 to B32 (Tables 10 and 11)

A fine wiring pattern was formed on an insulated base (trade name:E-679, a glass cloth-epoxy resin laminated plate, manufactured byHitachi Chemical Co., Ltd.), and then an insulated protecting resin(trade name: PSR 4000 AUS5, manufactured by Taiyo Ink Mfg. Co., Ltd.)was applied onto surfaces of the resultant except gold-plated terminalson a semiconductor element mounting side surface thereof andoutside-connecting terminals on the opposite side surface, so as to forma semiconductor mounting substrate of length 40 mm×width 40 mm×thickness1.3 mm. The substrate was dried at 120° C. for 2 hours, and then asemiconductor element of length 6 mm×width 5 mm×thickness 0.4 mm (area:30 mm²) which had a bump diameter of 175 μm and a bump pitch of 400 μm,was mounted on the substrate by IR reflow treatment at 260° C. for 10seconds. The bump height after the mounting was 120 μm. Next, theencapsulating epoxy resin molding materials B1 to B3 and B7 to B19 wereeach used and molded into a size of length 12 mm×width 12 mm×thickness1.2 mm on the semiconductor element mounted surface by vacuum transfermolding under the above-mentioned conditions. In this way, flip chip BGAdevices of Examples B17 to B32 were each produced.

Comparative Examples B4 to B6 (Table 13)

Semiconductor devices of Comparative Examples B4 to B6 were produced inthe same way as in Examples B17 to B32 except that the encapsulatingepoxy resin molding materials B4 to B6 were used.

[Production of Semiconductor Devices B3 (Flip Chip BGAs)]

Next, the encapsulating epoxy resin molding materials B1 to B19 wereused to produce semiconductor devices of Comparative Examples B7 to B25.Encapsulation with each of the encapsulating epoxy resin moldingmaterials was performed by using a transfer molding machine to mold thematerial under conditions of a mold temperature of 165° C., a moldingpressure of 9.8 MPa, a vacuum degree of 530 Pa, and a curing time of 90seconds and then curing the molded material at 180° C. for 5 hours.

Comparative Examples 7 to 25 (Tables 14 and 15)

A fine wiring pattern was formed on an insulated base (trade name:E-679, a glass cloth-epoxy resin laminated plate, manufactured byHitachi Chemical Co., Ltd.), and then an insulated protecting resin(trade name: PSR 4000 AUS5, manufactured by Taiyo Ink Mfg. Co., Ltd.)was applied onto surfaces of the resultant except gold-plated terminalson a semiconductor element mounting side surface thereof andoutside-connecting terminals on the opposite side surface, so as to forma semiconductor mounting substrate of length 40 mm×width 40 mm×thickness1.3 mm. The substrate was dried at 120° C. for 2 hours, and then asemiconductor element of length 5 mm×width 4 mm×thickness 0.4 mm (area:20 mm²), which had a bump diameter of 250 μm and a bump pitch of 700 μm,was mounted on the substrate by IR reflow treatment at 260° C. for 10seconds. The bump height after the mounting was 180 μm. Next, theencapsulating epoxy resin molding materials B1 to B19 were each used andmolded into a size of length 12 mm×width 12 mm×thickness 2.5 mm on thesemiconductor element mounted surface by vacuum transfer molding underthe above-mentioned conditions. In this way, flip chip BGA devices ofComparative Examples B7 to B25 were each produced.

The amounts of voids generated in the produced semiconductor devices ofExamples B1 to B32 and Comparative Examples B1 to B25 were tested andevaluated. The evaluation results are shown in Tables 8 to 15. TABLE 8Evaluation results 1 of semiconductor devices (semiconductor devices B1)Examples B Properties 1 2 3 4 5 6 7 8 9 Encapsulating epoxy resin 1 2 37 8 9 10 11 12 molding material B Amount of generated voids 2/20 0/202/20 3/20 4/20 3/20 0/20 0/20 1/20

TABLE 9 Evaluation results 2 of semiconductor devices (semiconductordevices B1) Examples B Properties 10 11 12 13 14 15 16 Encapsulatingepoxy 13 14 15 16 17 18 19 resin molding material B Amount of generated0/20 0/20 2/20 2/20 0/20 0/20 3/20 voids

TABLE 10 Evaluation results 3 of semiconductor devices (semiconductordevices B2) Examples B Properties 17 18 19 20 21 22 23 24 25Encapsulating epoxy resin 1 2 3 7 8 9 10 11 12 molding material B Amountof generated voids 1/20 0/20 1/20 3/20 3/20 2/20 0/20 0/20 0/20

TABLE 11 Evaluation results 4 of semiconductor devices (semiconductordevices B2) Examples B Properties 26 27 28 29 30 31 32 Encapsulatingepoxy 13 14 15 16 17 18 19 resin molding material B Amount of 0/20 0/201/20 1/20 0/20 0/20 2/20 generated voids

TABLE 12 Evaluation results 5 of semiconductor devices (semiconductordevices B1) Comparative Examples B Properties 1 2 3 Encapsulating epoxyresin 4 5 6 molding material B Amount of generated voids 11/20 unfilled18/20

TABLE 13 Evaluation results 6 of semiconductor devices (semiconductordevices B2) Comparative Examples B Properties 4 5 6 Encapsulating epoxyresin 4 5 6 molding material B Amount of generated voids 8/20 unfilled10/20

TABLE 14 Evaluation results 7 of semiconductor devices (semiconductordevices B3) Comparative Examples B Properties 7 8 9 10 11 12 13 14 15 16Encapsulating epoxy resin 1 2 3 4 5 6 7 8 9 10 molding material B Amountof generated voids 0/20 0/20 0/20 2/20 3/20 2/20 0/20 0/20 0/20 0/20

TABLE 15 Evaluation results 8 of semiconductor devices (semiconductordevices B3) Comparative Examples B Properties 17 18 19 20 21 22 23 24 25Encapsulating epoxy resin 11 12 13 14 15 16 17 18 19 molding material BAmount of generated voids 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20[Reliability Evaluation]

Examples B33 to B48 (Tables 16 and 17), and Comparative Examples B26 toB28 (Table 17)

Next, the encapsulating epoxy resin molding materials B1 to B19 wereeach used to evaluate various reliabilities thereof (reflow resistance,humidity resistance and high-temperature leaving property). Theevaluation results are shown in Tables 16 and 17. For the evaluation,semiconductor devices 2 produced under the same conditions as describedabove were used. TABLES 16 Reliability 1 (semiconductor devices B2)Examples B Properties 33 34 35 36 37 38 39 40 41 42 Encapsulating epoxyresin 1 2 3 7 8 9 10 11 12 13 molding material B Reflow resistance  72 h0/5  0/5  0/5  0/5  0/5  0/5  0/5  0/5  0/5  0/5   96 h 0/5  0/5  0/5 1/5  1/5  0/5  0/5  0/5  0/5  0/5  168 h 1/5  2/5  1/5  3/5  5/5  0/5 0/5  0/5  0/5  0/5  336 h 3/5  3/5  4/5  5/5  5/5  3/5  2/5  2/5  2/5 0/5  Humidity resistance 100 h 0/10 0/10 0/10 0/10 0/10 0/10 0/10 0/100/10 0/10 300 h 0/10 0/10 0/10 0/10 0/10 0/10 0/10 0/10 0/10 0/10 500 h0/10 0/10 0/10 0/10 0/10 0/10 0/10 0/10 0/10 0/10 1000 h  0/10 0/10 0/100/10 0/10 0/10 0/10 0/10 0/10 0/10 High-temperature 100 h 0/10 0/10 0/100/10 0/10 0/10 0/10 0/10 0/10 0/10 leaving property 300 h 0/10 0/10 0/100/10 0/10 0/10 0/10 0/10 0/10 0/10 500 h 2/10 2/10 3/10 1/10 2/10 8/105/10 6/10 3/10 5/10 1000 h  10/10  10/10  10/10  7/10 7/10 10/10  10/10 10/10  8/10 10/10 

TABLES 17 Reliability 2 (semiconductor devices B2) Comparative ExamplesB Examples B Properties 43 44 45 46 47 48 26 27 28 Encapsulating epoxyresin 14 15 16 17 18 19 4 5 6 molding material B Reflow resistance  72 h0/5  3/5 0/5  0/5  0/5  0/5  0/5  5/5 0/5  96 h 0/5  5/5 0/5  0/5  0/5 0/5  2/5  5/5 4/5 168 h 0/5  5/5 0/5  0/5  0/5  3/5  4/5  5/5 5/5 336 h0/5  5/5 0/5  1/5  2/5  5/5  5/5  5/5 5/5 Humidity resistance 100 h 0/10 0/10 0/10 0/10 0/10 0/10 3/10 10/10  5/10 300 h 0/10  0/10 0/10 0/100/10 0/10 5/10 10/10  8/10 500 h 0/10  0/10 0/10 2/10 0/10 0/10 8/1010/10 10/10 1000 h  0/10  0/10 0/10 5/10 2/10 0/10 10/10  10/10 10/10High-temperature 100 h 0/10 0/5 0/10 0/10 0/10 0/10 0/10  0/10  0/10leaving property 300 h 2/10 0/5 0/10 0/10 0/10 0/10 0/10  0/10  0/10 500h 8/10 3/5 0/10 0/10 0/10 0/10 3/10  2/10  2/10 1000 h  10/10  5/5 0/102/10 0/10 0/10 9/10 10/10 10/10

In the semiconductor devices of Comparative Examples B1 to B6, whichwere encapsulated by the encapsulating epoxy resin molding materials B4to B6 containing no inorganic filler (C) having an average particle sizeof 15 μm or less and a specific surface area of 3.0 to 6.0 m²/g, a largeamount of voids was generated and unfilled portions were generated.Thus, the filling ability thereof was poor. In the semiconductor devicesof Comparative Examples B26 to B28, the reflow resistance and thehumidity resistance thereof lowered.

On the other hand, in all of the semiconductor devices of Examples B1 toB32, which were encapsulated by the encapsulating epoxy resin moldingmaterials B1 to B3 and B7 to B19 each containing all of the components(A) to (C), the amount of generated voids was small. Thus, the fillingability was excellent. The semiconductor devices of Examples B33 and B48had excellent reflow resistance and humidity resistance.

In the semiconductor devices of Comparative Examples B7 to B25, whichdid not have one or more of the structures (a) to (d) of the invention,the amount of generated voids was small and thus the filling ability wasexcellent. Between the encapsulating epoxy resin molding materials B1 toB3 and B7 to B19 and the encapsulating epoxy resin molding materials B4to B6, no significant difference was found out.

Examples B45 to B48 were excellent in high-temperature leaving property,these examples being encapsulated by the encapsulating epoxy resinmolding material B16 containing no flame retardant and the encapsulatingepoxy resin molding materials B17 and B19, which each contained one ofthe non-halogen flame retardants.

The encapsulating epoxy resin molding materials for flip chip packagingaccording to Examples B have a high filling ability required for anunder filler and give only a small amount of molding defects such asvoids. Moreover, the molding materials are also excellent inreliabilities such as reflow resistance and humidity resistance. Thus,the industrial value thereof is large.

[Evaluating Methods]

(1) Spiral Flow (Index of Fluidity)

A spiral flow measuring mold according to EMMI-1-66 was used to mold anencapsulating epoxy resin molding material by means of a transfermolding machine under conditions of a mold temperature of 180° C., amolding pressure of 6.9 MPa, and a curing time of 90 seconds, and thenthe flowing distance thereof was obtained.

(2) Disc Flow

A disc flow measuring planar molds having a top part of 200 mm (W)×200mm (D)×25 mm (H) and a bottom part of 200 mm (W)×200 mm (D)×15 mm (H)was used, and precisely-weighed five grams of a sample (encapsulatingepoxy resin molding material) was put onto the center of the bottom partheated to 180° C. After 5 seconds therefrom, the top part heated to 180°C. was tightened thereon, and then the sample was compression-molded ata load of 78 N for a curing time of 90 seconds. The long diameter (mm)and the short diameter (mm) of the molded product were measured with avernier micrometer. The average value thereof was defined as the discflow.

(3) Hardness at Hot Time

An encapsulating epoxy resin molding material was molded into a dischaving a diameter of 50 mm and a thickness of 3 mm under theabove-mentioned conditions. Immediately after the material was molded,the hardness thereof was measured with a Shore D hardness meter.

(4) Flame Resistance

A mold for molding a test piece having a thickness of 1/16 inch was usedto mold an encapsulating epoxy resin molding material under theabove-mentioned conditions and then cured at 180° C. for 5 hours. Theflame resistance thereof was evaluated in accordance with UL-94 testingmethod.

(5) Amount of Generated Voids

An ultrasonic inquiry video system (HYE-HOCUS model, manufactured byHitachi Construction Machinery Co., Ltd.) was used to observe the insideof semiconductor devices, thereby observing whether voids having adiameter of 0.1 mm or more were generated or not. An evaluation was madeon the basis of the ratio of the number of semiconductor devices whereinvoids were generated to the number of the semiconductor devices tested.

(6) Reflow Resistance

Each of the semiconductor devices 3 was humidified at 85° C. and 85 % RHand subjected to reflow treatment at 260° C. for 10 seconds at intervalsof a given time, and it was observed whether cracks were generated ornot. An evaluation was made on the basis of the number of packageswherein cracks were generated out of the number (5) of the packagestested.

(7) Humidity Resistance

Each of the semiconductor devices 3 was subjected to pre-treatment, andthen humidified. At intervals of a given time, a snapping defect basedon corrosion of the aluminum wiring therein was examined. An evaluationwas made on the basis of the number of bad packages out of the number(10) of the packages tested.

In the pre-treatment, each of the flat packages was humidified at 85° C.and 85% RH for 72 hours, and then subjected to vapor phase reflowtreatment at 215° C. for 90 seconds. The humidification thereafter wasperformed at 0.2 MPa and 121° C.

(8) High-Temperature Leaving Property

Each of the semiconductor devices 3 was kept in a thermostat of 200° C.temperature, and was taken out at intervals of a given time. Thetaken-out semiconductor device was subjected to a continuity test. Thehigh-temperature leaving property thereof was evaluated on the basis ofthe number of packages poor in continuity out of the number (10) of thepackages tested.

Examples C

[Production of Encapsulating Epoxy Resin Molding Materials]

Components described below were blended so that the amount of each ofthe components would be a part or parts by weight shown in Table 18, andthen the resultant was roll-kneaded at a kneading temperature of 80° C.for a kneading time of 10 minutes. In this way, encapsulating epoxyresin molding materials according to Examples C1 to C4 and ComparativeExamples C1 to C4 were produced.

(Epoxy Resin)

-   Epoxy resin A: a biphenyl epoxy resin having an epoxy equivalent of    196 and a melting point 106° C. (trade name: EPIKOTE YX-4000H,    manufactured by Japan Epoxy Resins Co., Ltd.)-   Epoxy resin B: a biphenyl epoxy resin having an epoxy equivalent of    176 and a melting point 125° C. (trade name: EPIKOTE YL-6121H,    manufactured by Japan Epoxy Resins Co., Ltd.)-   Epoxy resin C: a triphenolmethane epoxy resin having a softening    point of 60° C. and a melt viscosity of 2.4 poises at 150° C. (trade    name: EPIKOTE E1032H, manufactured by Japan Epoxy Resins Co., Ltd.)-   Epoxy resin D: a bisphenol F epoxy resin having an epoxy equivalent    of 186 and a melting point of 75° C. (trade name: YSLV-80XY,    manufactured by Nippon Steel Chemical Co., Ltd.)    (Curing Agents)-   Phenol resin A: a triphenolmethane phenol resin having a hydroxyl    equivalent of 103 and a melt viscosity of 1.3 poises at 150° C.    (trade name: MEH-7500-3S, manufactured by Meiwa Plastic Industries,    Ltd.)-   Phenol resin B: a phenol Novolak resin having a softening point of    80° C. and a hydroxyl equivalent of 106 (trade name: H-1,    manufactured by Meiwa Plastic Industries, Ltd.)    (Curing Accelerator)-   Curing accelerator A: an adduct of triphenylphosphine and    p-benzoquinone-   Curing accelerator B: an adduct of tris(4-methylphenyl)phosphine and    p-benzoquinone    (Releasing Agent)-   Releasing agent A: a polyethylene wax (manufactured by Clariant Co.)-   Releasing agent B: a montanoic acid ester (manufactured by Clariant    Co.)    (Flame Retardant)-   Flame retardant: a bisphenol A brominated epoxy resin having an    epoxy equivalent of 375, a softening point of 80° C. and a bromine    content of 48% by weight (trade name: ESB-400T, manufactured by    Sumitomo Chemical Co., Ltd.).-   Flame retardant aid: antimony trioxide    (Coloring Agent)-   Carbon black: carbon black (trade name: MA-100, manufactured by    Mitsubishi Chemical Corp.)    (Other Additives)-   Additive A: a polyether modified silicone oil (Dow Corning Toray    Silicone Co., Ltd.)-   Additive B: an epoxy modified silicone oil (Dow Corning Toray    Silicone Co., Ltd.)-   Additive C: hydrotalcite-   Additive D: bismuth hydroxide    (Coupling Agents)-   Coupling agent A: γ-anilinopropyltrimethoxysilane (anilinosilane)-   Coupling agent B: methyltrimethoxysilane-   Coupling agent C: γ-mercaptopropyltrimethoxysilane-   Coupling agent D: γ-glycidoxypropyltrimethoxysilane (epoxysilane)    (Inorganic Fillers)

Fused silicas: all spherical fused silicas TABLE 18 Examples C 1 2 3 4 56 7 8 Epoxy resin A 6.06 5.96 5.06 Epoxy resin B 6.84 6.97 6.26 Epoxyresin C 5.41 6.74 Epoxy resin D 2.25 0.9 Phenol resin 3.6 4.42 4.51 4.873.54 3.54 4.95 4.07 Curing accelerator 0.32 0.24 0.25 0.18 0.32 0.160.16 0.18 Releasing agent 0.32 0.14 0.33 0.15 0.32 0.06 0.15 0.12 Flameretardant 1.07 1.21 1.23 1.35 1.05 0.56 1.35 1.1 Flame retardant aid1.07 1.21 1.23 1.35 1.05 0.34 1.35 1.1 Carbon black 0.36 0.24 0.25 0.270.35 0.15 0.27 0.22 Additive 1.72 1.93 1.97 1.71 1.68 0.06 2.16 1.76Coupling agent A *1 0.31 0.35 0.17 0.19 0.47 0.39 0.32 Coupling agent B*2 0.21 0.24 0.12 0.14 0.32 0.25 0.27 0.22 Coupling agent C *3 0.01 0.010.01 0.01 0.01 0.01 0.01 0.01 Coupling agent D *4 0.37 Fused silica A *576.46 76.48 80.46 Fused silica B *6 66.52 66.5 65.35 Fused silica C *756.92 Fused silica D *8 76 Fused silica E *9 8.49 8.47 8.93 8.47 Fusedsilica F *10 16.65 16.65 16.31 24.37 Average particle size (μm) 13.58.46 8.46 8.46 13.5 13.5 4.3 15.3 Specific surface area (m2/g) 3.43 4.624.62 4.62 3.43 3.43 3.04 3.4 Coupling coverage ratio (%) 0.77 0.65 0.340.375 1.13 0.86 1.14 0.79 Heating reduction ratio (% by mass) 0.1850.223 0.142 0.142 0.279 0.254 0.216 0.191 Void area (mm2) 0.103 0.1240.115 0.11 0.181 0.146 0.149 0.175Abbreviations in the Table have the following meanings.*1: minimum coverage area: 307.0 m²/g*2: minimum coverage area: 575.6 m²/g*3: minimum coverage area: 399.4 m²/g*4: minimum coverage area: 315.2 m²/g*5: average particle size: 11.7 μm, specific surface area: 3.2 m²/g*6: average particle size: 10.8 μm, specific surface area: 4.2 m²/g*7: average particle size: 9.3 μm, specific surface area: 1.6 m²/g*8: average particle size: 13.5 μm, specific surface area: 3.2 m²/g*9: average particle size: 0.6 μm, specific surface area: 5.5 m²/g*10: average particle size: 0.5 μm, specific surface area: 6.3 m²/g(1) Void Area Evaluating Method

A semiconductor element of length 9.1 mm×width 8.2 mm×thickness 0.4 mm(area: 74.6 mm²) which had a bump diameter of 200 μm, a bump depth of135 μm and a bump pitch of 490 μm was fixed onto the central position ofa cavity, and an encapsulating epoxy resin molding material was used toperform vacuum transfer molding under the following molding conditions:a mold temperature of 165° C., a molding pressure of 4.4 MPa, a vacuumdegree of 0.1 MPa, a cavity inside filling time of 7.5 seconds, and acuring time of 90 seconds. In this way, a molded product of length 14mm×width 22 mm×thickness 0.7 mm was produced.

Voids generated in the bump portions of the molded product werephotographed at a magnification of X. From the area SP of voids on thephotograph and the magnification, the actual area of the voids wascalculated, using the following equation (xx):SB=SP/X   (xx)

The encapsulating epoxy resin molding material of the present inventionfor flip chip packaging has a high filling ability required for an underfiller, gives only a small amount of molding defects such as voids, andfurther is excellent in reliabilities such as reflow resistance andhumidity resistance. Thus, the industrial value thereof is large.

Examples D

The present invention will be described by way of the following workingexamples. However, the scope of the invention is not limited to theseexamples. Each encapsulating epoxy resin molding material and eachsemiconductor device were evaluated on the basis of evaluating methodswhich will be described later unless otherwise specified.

[Production of Encapsulating Epoxy Resin Molding Materials]

Components described below were blended so that the amount of each ofthe components would be a part or parts by weight shown in Table 19 or20, and then the resultant was kneaded with a kneader at a blendingpowder supplying amount of 200 kg/h. In this way, encapsulating epoxyresin molding materials D1 to D13 were produced.

(Epoxy Resins)

As epoxy resins, the following were used: a biphenyl epoxy resin havingan epoxy equivalent of 196 and a melting point of 106° C. (trade name:EPIKOTE YX-4000H, manufactured by Japan Epoxy Resins Co., Ltd.); abisphenol F epoxy resin having an epoxy equivalent of 186 and a meltingpoint of 75° C. (trade name: YSLV-80XY, manufactured by Nippon SteelChemical Co., Ltd.); a sulfur-containing epoxy resin having an epoxyequivalent of 245 and a melting point of 110° C. (trade name:YSLV-120TE, manufactured by Nippon Steel Chemical Co., Ltd.); ano-cresol Novolak epoxy resin having an epoxy equivalent of 195 and amelting point of 65° C. (trade name: ESCN-190, manufactured by SumitomoChemical Co., Ltd.); and a triphenolmethane epoxy resin (apolyfunctional epoxy resin) having an epoxy equivalent of 170, asoftening point of 70° C., and a melt viscosity of 3.1 poises at 150° C.(tradename: EPIKOTE E1032H, manufactured by Japan Epoxy Resins Co.,Ltd.).

(Curing Agents)

As curing agents, the following were used: a phenol/aralkyl resin havinga softening point of 70° C. and a hydroxyl equivalent of 175 (tradename: Milex (transliteration) XL-225, manufactured by Mitsui Chemicals,Inc.); a phenol Novolak resin having a softening point of 80° C. and ahydroxyl equivalent of 106 (trade name: H-1, manufactured by MeiwaPlastic Industries, Ltd.); and a polyfunctional phenol resin having asoftening point of 83° C. and a hydroxyl equivalent of 103 (trade name:MEH-7500-3S, manufactured by Meiwa Plastic Industries, Ltd.).

(Curing Accelerator)

As an accelerator, an adduct (curing accelerator) of triphenylphosphineand p-benzoquinone was used.

(Coupling Agents)

As coupling agents, the following were used:γ-glycidoxypropyltrimethoxysilane (epoxysilane), and a silane couplingagent containing a secondary amino group(γ-anilinopropyltrimethoxysilane (anilinosilane)).

(Flame Retardants)

As flame retardants, the following were used: antimony trioxide, and abisphenol A brominated epoxy resin having a softening point of 80° C.and a bromine content of 48% by weight (trade name: ESB-400T,manufactured by Sumitomo Chemical Co., Ltd.).

(Silicones)

As silicones, methylphenylsilicone and silicone rubber were used.

(Inorganic Fillers)

As inorganic fillers, there were used spherical fused silicas having anaverage particle size of 28 μm, an average particle size of 20 μm, anaverage particle size of 8 μm, and an average particle size of 0.5 μm,respectively.

(Other Additives)

As other additives, a higher fatty acid wax and carbon black were used.TABLE 19 Epoxy resin molding materials D Items 1 2 3 4 5 6 7 o-CresolNovolak 7.4 6.7 4.6 epoxy resin Biphenyl epoxy resin 6.9 7 1.4Sulfur-containing epoxy resin Polyfunctional 4 5.5 epoxy resin BisphenolF epoxy 3.6 2.3 resin Bisphenol A 1.3 1.4 1.2 1.2 1.3 1.2 0.7 brominatedepoxy resin Phenol Novolak resin 1.8 Phenol aralkyl resin 6.2 5.7 2.2Polyfunctional phenol 4.8 4.9 4.5 4.6 resin Adduct of 0.2 0.2 0.2 0.20.2 0.2 0.1 triphenylphosphine and p-benzoquinone Epoxysilane 0.4 0.4Anilinosilane 0.4 0.2 0.4 0.2 0.3 Higher fatty acid wax 0.1 0.1 0.1 0.10.1 0.1 0.1 Carbon black 0.3 0.3 0.2 0.2 0.2 0.2 0.1 Antimony trioxide1.3 1.4 1.2 1.2 0.5 0.5 0.4 Silicone rubber Methyl phenyl silicone 1.31.4 1.2 1.2 Fused silica having an average particle size of 28 μm Fusedsilica having an 75.3 76.5 average particle size of 20 μm Fused silicahaving an 66.1 65.9 67.3 67.3 79.4 average particle size of 8 μm Fusedsilica having an 16.6 16.4 16.8 16.8 8.4 8.5 8.9 average particle sizeof 0.5 μm Total 100 100 100 100 100 100 100

TABLE 20 Epoxy resin molding materials D Items 8 9 10 11 12 13 o-CresolNovolak epoxy resin Biphenyl epoxy resin 6.7 5.1 6.3 5.2Sulfur-containing 5.1 epoxy resin Polyfunctional epoxy 7.6 resinBisphenol F epoxy resin Bisphenol A 1.2 0.6 0.9 1.3 1.1 0.9 brominatedepoxy resin Phenol Novolak resin Phenol aralkyl resin 6.6 4.9 2.9Polyfunctional phenol 4.9 1.9 1.5 resin Adduct of 0.3 0.2 0.2 0.1 0.20.2 triphenylphosphine and p-benzoquinone Epoxysilane 0.4 Anilinosilane0.3 0.3 0.4 0.3 0.3 Higher fatty acid wax 0.1 0.1 0.1 0.1 0.1 0.1 Carbonblack 0.1 0.1 0.2 0.3 0.2 0.2 Antimony trioxide 0.5 0.3 0.4 1.3 1.1 0.9Silicone rubber 3.3 2.7 Methyl phenyl silicone 1.3 Fused silica havingan 50.5 61.9 67.5 average particle size of 28 μm Fused silica having an74.4 77.0 79.3 average particle size of 20 μm Fused silica having an25.2 17.7 17.9 average particle size of 8 μm Fused silica having an 8.48.9 4.5 8.3 8.5 8.7 average particle size of 0.5 μm Total 100 100.1 100100 100 100

Properties of the produced encapsulating epoxy resin molding materialsD1 to D13 were evaluated about test items shown in tables (spiral flow,disc flow, hardness at hot time, bending modulus, mold shrinkage ratio,and glass transition temperature) The results are shown in Tables 21 and22. TABLE 21 Epoxy resin molding materials D Items Unit 1 2 3 4 5 6 7Spiral flow inch 90 73 92 93 53 52 45 Disc flow mm 125 107 117 114 79 9288 Shore D hardness at hot time — 77 85 86 80 82 81 89 Bending modulusGPa 17.8 18.3 18.5 18.5 21.6 22.3 23.8 Mold shrinkage ratio % 0.1890.122 0.13 0.142 0.344 0.339 0.165 Glass transition temperature ° C. 163184 165 161 140 142 146

TABLE 22 Epoxy resin molding materials D Items Unit 8 9 10 11 12 13Spiral flow inch 58 54 47 77 75 57 Disc flow mm 90 100 93 117 95 86Shore D hardness at hot time — 84 81 80 84 75 82 Bending modulus GPa20.8 23.4 25.6 17.1 19.7 22.2 Mold shrinkage ratio % 0.362 0.169 0.1640.177 0.181 0.145 Glass transition temperature ° C. 118 138 132 185 163159[Production of Semiconductor Devices D1 (Flip Chip BGAs)]

Next, the encapsulating epoxy resin molding materials D1 to D13 wereused to produce semiconductor devices of Examples D1 to D10 andComparative Examples D1 to D3. Encapsulation with each of theencapsulating epoxy resin molding materials was performed by using atransfer molding machine to mold the material under conditions of amolding temperature of 180° C., a molding pressure of 6.9 MPa and acuring time of 90 seconds and then curing the molded material at 180° C.for 5 hours.

Examples D1 to D10 (Tables 23 and 24): A fine wiring pattern was formedon an insulated base (trade name: E-679, a glass cloth-epoxy resinlaminated plate, manufactured by Hitachi Chemical Co., Ltd.), and thenan insulated protecting resin (trade name: PSR 4000 AUS5, manufacturedby Taiyo Ink Mfg. Co., Ltd.) was applied onto surfaces of the resultantexcept gold-plated terminals on a semiconductor element mounting sidesurface thereof and outside-connecting terminals on the opposite sidesurface, so as to form a semiconductor mounting substrate of length 40mm×width 80 mm×thickness 0.6 mm. The substrate was dried at 120° C. for2 hours, and then a semiconductor element of length 9 mm×width 8mm×thickness 0.4 mm (area: 72 mm²) to which 160 bumps having a bumpdiameter of 145 μm and a bump pitch of 200 μm were fitted, was mountedon the substrate by IR reflow treatment at 260° C. for 10 seconds. Thebump height after the mounting was 110 μm. Next, the encapsulating epoxyresin molding materials D1 to D4; D7 and D9 to D13 were each used andmolded into a size of length 30 mm×width 70 mm×thickness 0.8 mm on thesemiconductor element mounted surface by vacuum transfer molding underthe above-mentioned conditions. In this way, flip chip BGA devices ofExamples D1 to D10 were each produced.

Comparative Examples D1 to D3 (Table 25)

The encapsulating epoxy resin molding materials D5, D6 and D8 were usedto produce semiconductor devices of Comparative Examples D1 to D3 in thesame way as in Examples D1 to D10. TABLE 23 Example D Items 1 2 3 4 5Epoxy resin molding material D 1 2 3 4 7 External form of a substratefor Length 40 mm × width mounting a semiconductor element 80 mm ×thickness 0.6 mm Semiconductor element external form Length 9 mm × width8 mm × thickness 0.4 mm Semiconductor element bump diameter 145 μmSemiconductor element bump pitch 200 μm Semiconductor element bumpnumber 160 Semiconductor element encapsulation Length 30 mm × widthexternal form 70 mm × thickness 0.8 mm

TABLE 24 Example D Items 6 7 8 9 10 Epoxy resin molding material D 9 1011 12 13 External form of a substrate for Length 40 mm × width mountinga semiconductor element 80 mm × thickness 0.6 mm Semiconductor elementexternal form Length 9 mm × width 8 mm × thickness 0.4 mm Semiconductorelement bump diameter 145 μm Semiconductor element bump pitch 200 μmSemiconductor element bump number 160 Semiconductor elementencapsulation Length 30 mm × width external form 70 mm × thickness 0.8mm

TABLE 25 Comparative Example D Items 1 2 3 Epoxy resin molding materialD 5 6 8 External form of a substrate for mounting Length a semiconductorelement 40 mm × width 80 mm × thickness 0.6 mm Semiconductor elementexternal form Length 9 mm × width 8 mm × thickness 0.4 mm Semiconductorelement bump diameter 145 μm Semiconductor element bump pitch 200 μmSemiconductor element bump number 160 Semiconductor elementencapsulation external form Length 30 mm × width 70 mm × thickness 0.8mm[Production of Semiconductor Devices D2 (Flip Chip BGAs)]

Next, the encapsulating epoxy resin molding materials D1 to D13 wereused to produce semiconductor devices of Examples D11 to D20 andComparative Examples D4 to D6. Encapsulation with each of theencapsulating epoxy resin molding materials was performed by using atransfer molding machine to mold the material under conditions of amolding temperature of 180° C., a molding pressure of 6.9 MPa and acuring time of 90 seconds and then curing the molded material at 180° C.for 5 hours.

Examples D11 to D20 (Tables 26 and 27)

A fine wiring pattern was formed on an insulated base (trade name:E-679, a glass cloth-epoxy resin laminated plate, manufactured byHitachi Chemical Co., Ltd.), and then an insulated protecting resin(trade name: PSR 4000 AUS5, manufactured by Taiyo Ink Mfg. Co., Ltd.)was applied onto surfaces of the resultant except gold-plated terminalson a semiconductor element mounting side surface thereof andoutside-connecting terminals on the opposite side surface, so as to forma semiconductor mounting substrate of length 50 mm×width 100mm×thickness 0.6 mm. The substrate was dried at 120° C. for 2 hours, andthen a semiconductor element of length 9 mm×width 8 mm×thickness 0.4 mm(area: 72 mm²), to which 160 bumps having a bump diameter of 145 μm anda bump pitch of 200 μm were fitted, was mounted on the substrate by IRreflow treatment at 260° C. for 10 seconds. The bump height after themounting was 110 μm. Next, the encapsulating epoxy resin moldingmaterials D1 to D4, D7 and D9 to D13 were each used and molded into asize of length 40 mm×width 90 mm×thickness 0.8 mm on the semiconductorelement mounted surface by vacuum transfer molding under theabove-mentioned conditions. In this way, flip chip BGA devices ofExamples D11 to D20 were each produced.

Comparative Examples D4 to D6 (Table 28)

The encapsulating epoxy resin molding materials D5, D6 and D8 were usedto produce semiconductor devices of Comparative Examples D4 to D6 in thesame way as in Examples D11 to D20. TABLE 26 Example D Items 11 12 13 1415 Epoxy resin molding material D 1 2 3 4 7 External form of a substratefor Length 50 mm × width mounting a semiconductor element 100 mm ×thickness 0.6 mm Semiconductor element external form Length 9 mm × width8 mm × thickness 0.4 mm Semiconductor element bump diameter 145 μmSemiconductor element bump pitch 200 μm Semiconductor element bumpnumber 160 Semiconductor element encapsulation Length 40 mm × widthexternal form 90 mm × thickness 0.8 mm

TABLE 27 Example D Items 16 17 18 19 20 Epoxy resin molding material D 910 11 12 13 External form of a substrate for Length 50 mm × widthmounting a semiconductor element 100 mm × thickness 0.6 mm Semiconductorelement external form Length 9 mm × width 8 mm × thickness 0.4 mmSemiconductor element bump diameter 145 μm Semiconductor element bumppitch 200 μm Semiconductor element bump number 160 Semiconductor elementencapsulation Length 40 mm × width external form 90 mm × thickness 0.8mm

TABLE 28 Comparative Example D Items 4 5 6 Epoxy resin molding materialD 5 6 8 External form of a substrate for Length 50 mm × width mounting asemiconductor element 100 mm × thickness 0.6 mm Semiconductor elementexternal form Length 9 mm × width 8 mm × thickness 0.4 mm Semiconductorelement bump diameter 145 μm Semiconductor element bump pitch 200 μmSemiconductor element bump number 160 Semiconductor elementencapsulation Length 40 mm × width external form 90 mm × thickness 0.8mm[Production of Semiconductor Devices 3 (Flip Chip BGAs)]

Next, the encapsulating epoxy resin molding materials D1 to D13 wereused to produce semiconductor devices of Examples D21 to D30 andComparative Examples D7 to D9. Encapsulation with each of theencapsulating epoxy resin molding materials was performed by using atransfer molding machine to mold the material under conditions of amolding temperature of 180° C., a molding pressure of 6.9 MPa and acuring time of 90 seconds and then curing the molded material at 180° C.for 5 hours.

Examples D21 to D30 (Tables 29 and 30)

A fine wiring pattern was formed on an insulated base (trade name:E-679, a glass cloth-epoxy resin laminated plate, manufactured byHitachi Chemical Co., Ltd.), and then an insulated protecting resin(trade name: PSR 4000 AUS5, manufactured by Taiyo Ink Mfg. Co., Ltd.)was applied onto surfaces of the resultant except gold-plated terminalson a semiconductor element mounting side surface thereof andoutside-connecting terminals on the opposite side surface, so as to forma semiconductor mounting substrate of length 60 mm×width 120mm×thickness 0.6 mm. The substrate was dried at 120° C. for 2 hours, andthen a semiconductor element of length 9 mm×width 8 mm×thickness 0.4 mm(area: 72 mm²) to which 160 bumps having a bump diameter of 145 μm and abump pitch of 200 μm were fitted, was mounted on the substrate by IRreflow treatment at 260° C. for 10 seconds. The bump height after themounting was 110 μm. Next, the encapsulating epoxy resin moldingmaterials D1 to D4, D7 and D9 to D13 were each used and molded into asize of length 50 mm×width 110 mm×thickness 0.8 mm on the semiconductorelement mounted surface by vacuum transfer molding under theabove-mentioned conditions. In this way, flip chip BGA devices ofExamples D21 to D30 were each produced.

Comparative Examples D7 to D9 (Table 31)

The encapsulating epoxy resin molding materials D5, D6 and D8 were usedto produce semiconductor devices of Comparative Examples D7 to D9 in thesame way as in Examples D21 to D30. TABLE 29 Example D Items 21 22 23 2425 Epoxy resin molding material D 1 2 3 4 7 External form of a substratefor Length 60 mm × width mounting a semiconductor element 120 mm ×thickness 0.6 mm Semiconductor element external form Length 9 mm × width8 mm × thickness 0.4 mm Semiconductor element bump diameter 145 μmSemiconductor element bump pitch 200 μm Semiconductor element bumpnumber 160 Semiconductor element encapsulation Length 50 mm × widthexternal form 110 mm × thickness 0.8 mm

TABLE 30 Example D Items 26 27 28 29 30 Epoxy resin molding material D 910 11 12 13 External form of a substrate for Length 60 mm × widthmounting a semiconductor element 120 mm × thickness 0.6 mm Semiconductorelement external form Length 9 mm × width 8 mm × thickness 0.4 mmSemiconductor element bump diameter 145 μm Semiconductor element bumppitch 200 μm Semiconductor element bump number 160 Semiconductor elementencapsulation Length 50 mm × width external form 110 mm × thickness 0.8mm

TABLE 31 Comparative Example D Items 7 8 9 Epoxy resin molding materialD 5 6 8 External form of a substrate for Length 60 mm × width mounting asemiconductor element 120 mm × thickness 0.6 mm Semiconductor elementexternal form Length 9 mm × width 8 mm × thickness 0.4 mm Semiconductorelement bump diameter 145 μm Semiconductor element bump pitch 200 μmSemiconductor element bump number 160 Semiconductor elementencapsulation Length 50 mm × width external form 110 mm × thickness 0.8mm

The produced semiconductor devices of Examples D1 to D30 and ComparativeExamples D1 to D9 were evaluated through tests about substrate warp.Their glass transition points, bending moduli, mold shrinkage ratios andfilling abilities at the time of molding the semiconductor element werecompared. The evaluation results are shown in Tables 32 to 35. TABLE 32Example D Items Unit 1 2 3 4 5 6 7 8 9 10 Epoxy resin molding material D— 1 2 3 4 7 9 10 11 12 13 Glass transition temperature ° C. 163 184 165161 146 138 132 185 163 159 Bending modulus GPa 17.8 18.3 18.5 18.5 23.823.4 25.6 17.1 19.7 22.2 Mold shrinkage ratio % 0.189 0.122 0.130 0.1420.165 0.169 0.164 0.177 0.181 0.145 substrate warp mm 0.9 1.1 1.1 1.04.5 3.8 4.2 1.1 2.4 1.8 filling ability when being molded Area % 100 100100 100 66 100 71 100 100 75

TABLE 33 Example D Items Unit 11 12 13 14 15 16 17 18 19 20 Epoxy resinmolding material D — 1 2 3 4 7 9 10 11 12 13 Glass transitiontemperature ° C. 163 184 165 161 146 138 132 185 163 159 Bending modulusGPa 17.8 18.3 18.5 18.5 23.8 23.4 25.6 17.1 19.7 22.2 Mold shrinkageratio % 0.189 0.122 0.130 0.142 0.165 0.169 0.164 0.177 0.181 0.145substrate warp mm 1.5 1.6 1.4 1.5 4.9 4.0 4.8 1.7 2.8 2.2 fillingability when being molded Area % 100 100 100 100 54 90 71 98 94 71

TABLE 34 Example D Items Unit 21 22 23 24 25 26 27 28 29 30 Epoxy resinmolding material D — 1 2 3 4 7 9 10 11 12 13 Glass transitiontemperature ° C. 163 184 165 161 146 138 132 185 163 159 Bending modulusGPa 17.8 18.3 18.5 18.5 23.8 23.4 25.6 17.1 19.7 22.2 Mold shrinkageratio % 0.189 0.122 0.130 0.142 0.165 0.169 0.164 0.177 0.181 0.145substrate warp mm 1.8 2.0 1.9 1.9 5.0 4.3 5.0 2.0 3.1 2.5 fillingability when being molded Area % 100 100 100 100 66 77 52 88 84 58

TABLE 35 Example D Items Unit 1 2 3 4 5 6 7 8 9 Epoxy resin moldingmaterial D — 5 6 8 5 6 8 5 6 8 Glass transition temperature ° C. 140 142118 140 142 118 140 142 118 Bending modulus GPa 21.6 22.3 20.8 21.6 22.320.8 21.6 22.3 20.8 Mold shrinkage ratio % 0.344 0.339 0.362 0.344 0.3390.362 0.344 0.339 0.362 substrate warp mm 10.5 12.8 8.8 13.6 15.1 10.215.5 18.0 12.7 filling ability when being molded Area % 62 84 95 52 7784 41 63 71

Comparative Examples 1 to 9, which were encapsulated by the epoxy resinmolding materials D5, D6 and D8 each satisfying none of conditions thatthe glass transition temperature based on TMA method is 150° C. orhigher, the bending modulus based on JIS K6911 is 19 GPa or less and themold shrinkage ratio based on JIS K6911 is 0.2% or less, each gave alarge substrate warp and exhibited poor filling ability when thematerials were each molded.

On the other hand, Examples 1 to 30, which were encapsulated by theepoxy resin molding materials D1 to D4, D7 and D9 to 10 each satisfyingat least one of the above-mentioned conditions, gave a small substratewarp and exhibited good filling ability when the materials were molded.Examples encapsulated by the epoxy resin molding materials D1 to D4 andD11 each satisfying all of the above-mentioned conditions gave asubstrate warp of 2.0 mm or less so as to be particularly good.Moreover, when the materials were molded, the amount of generated voidswas small so that the filling ability thereof was particularly good.

[Evaluating Method]

(1) Spiral Flow

A spiral flow measuring mold according to EMMI-1-66 was used to mold anencapsulating epoxy resin molding material by means of a transfermolding machine under conditions of a mold temperature of 180° C., amolding pressure of 6.9 MPa, and a curing time of 90 seconds, and thenthe flowing distance (inch) thereof was obtained.

(2) Disc Flow

A disc flow measuring planar molds having a top part of 200 mm (W)×200mm (D)×25 mm (H) and a bottom part of 200 mm (W)×200 mm (D)×15 mm (H)was used, and precisely-weighed five grams of a sample (encapsulatingepoxy resin molding material) was put onto the center of the bottom partheated to 180° C. After 5 seconds therefrom, the top part heated to 180°C. was tightened thereon, and then the sample was compression-molded ata load of 78 N for a curing time of 90 seconds. The long diameter (mm)and the short diameter (mm) of the molded product were measured with avernier micrometer. The average value thereof was defined as the discflow.

(3) Hardness at Hot Time

An encapsulating epoxy resin molding material was molded into a dischaving a diameter of 50 mm and a thickness of 3 mm under conditions ofmolding temperature of 180° C., a molding pressure of 6.9 MPa and acuring time of 90 seconds. Immediately after the material was molded,the hardness thereof was measured with a Shore D hardness meter.

(4) Bending Modulus

A mold for molding a bending test piece according to JIS K6911 was usedto mold a material by means of a transfer molding machine underconditions of a molding temperature of 180° C., a molding pressure of6.9 MPa and a curing time of 90 seconds. Thereafter, the molded materialwas cured at 180° C. for 5 hours, and the bending modulus thereof wasmeasured in accordance with the bending test method described in JISK6911.

(5) Mold Shrinkage Ratio

A mold for mold shrinkage ratio measurement according to JIS K6911 wasused to mold a material by means of a transfer molding machine underconditions of a molding temperature of 180° C., a molding pressure of6.9 MPa and a curing time of 90 seconds. Thereafter, the molded materialwas cured at 180° C. for 5 hours, and the mold shrinkage ratio thereofwas measured in accordance with the mold shrinkage ratio test methoddescribed in JIS K6911.

(6) Glass Transition Temperature

A mold for producing a test piece, 20 mm×4 mm×4 mm, was used to mold amaterial by means of a transfer molding machine under conditions of amolding temperature of 180° C., a molding pressure of 6.9 MPa and acuring time of 90 seconds. Thereafter, the molded material was cured at180° C. for 5 hours, and then a TMA device (TSC 1000) manufactured byMac Science Corp. was used to measure the glass transition temperatureand the thermal expansion coefficient thereof by TMA method(differential expansion method).

(7) Substrate Warp Amount

A flip chip GBA substrate subjected to resin-molding was put onto ahorizontal flat face. One end of the substrate along the longitudinaldirection thereof was fixed by means of a 50 g balance weight. Therising dimension of the other end from the flat face was read out up toa level of 1/10 mm by use of a metallic square.

(8) Filling Ratio at Molding Time

An ultrasonic inquiry video system (HYE-HOCUS model, manufactured byHitachi Construction Machinery Co., Ltd.) was used to observe the insideof semiconductor devices. The ratio (% by area) of the filled area tothe encapsulating area was calculated.

INDUSTRIAL APPLICABILITY

The encapsulating epoxy resin molding material of the present inventionfor flip chip packaging has a high filling ability required for an underfiller and gives only a small amount of molding defects such as voids.Thus, the industrial value thereof is large. Furthermore, theencapsulating epoxy resin molding material of the present invention forflip chip packaging has a low warp property required for an under fillerand exhibits a good flow characteristic. Thus, the industrial valuethereof is large.

It would be understood by those skilled in the art that the above arepreferred embodiments of this invention and various modifications andrevisions can be carried out without disobeying the spirit and the scopeof this invention.

1. An encapsulating epoxy resin molding material, comprising (A) anepoxy resin, (B) a curing agent, and (C) an inorganic filler, whereinthe inorganic filler (C) has an average particle size of 12 μm or lessand a specific surface area of 3.0 m²/g or more.
 2. An encapsulatingepoxy resin molding material, comprising (A) an epoxy resin, (B) acuring agent, and (C) an inorganic filler, wherein the inorganic filler(C) comprises 5% or more by weight of an inorganic filler having amaximum particle size of 63 μm or less and particle sizes of 20 μm ormore.
 3. An encapsulating epoxy resin molding material, comprising (A)an epoxy resin, (B) a curing agent, and (C) an inorganic filler, theinorganic filler (C) having an average particle size of 15 μm or lessand a specific surface area of 3.0 to 6.0 m²/g, and the molding materialused in a semiconductor device having one or more of the followingstructures (a1) to (d1): (a1) a structure wherein a bump height of aflip chip is 150 μm or less, (b1) a structure wherein a bump pitch ofthe flip chip is 500 μm or less, (c1) a structure wherein an area of asemiconductor chip is 25 mm² or more, and (d1) a structure wherein athickness of a package, in which the semiconductor chip is disposed on amounting substrate, is 2 mm or less.
 4. An encapsulating epoxy resinmolding material, comprising (A) an epoxy resin, (B) a curing agent, and(C) an inorganic filler, and satisfying at least one of the followingconditions: the glass transition temperature based on TMA method is 150°C. or higher; the bending modulus based on JIS-K 6911 is 19 GPa or less;and the mold shrinkage ratio based on JIS-K 6911 is 0.2% or less.
 5. Theencapsulating epoxy resin molding material according to any one ofclaims 1 to 4, wherein the melt density of the epoxy resin (A) is 2poises or less at 150° C.
 6. The encapsulating epoxy resin moldingmaterial according to any one of claims 1 to 4, wherein the epoxy resin(A) comprises at least oen of a biphenyl epoxy resin, a bisphenol Fepoxy resin, a stylbene epoxy resin, a sulfur-containing epoxy resin, aNovolak epoxy resin, a dicyclopentadiene epoxy resin, a naphthaleneepoxy resin and a triphenylmethane epoxy resin.
 7. The encapsulatingepoxy resin molding material according to any one of claims 1 to 4,wherein the melt density of the curing agent (B) is 2 poises or less at150° C.
 8. The encapsulating epoxy resin molding material according toany one of claim 1 to4, wherein the curing agent (B) comprises at leastone of a biphenyl phenol resin, an aralkyl phenol resin, adicyclopentadiene phenol resin, a triphenylmethane phenol resin, and aNovolak phenol resin.
 9. The encapsulating epoxy resin molding materialaccording to any one of claims 1 to 4, further comprising a curingaccelerator(F).
 10. The encapsulating epoxy resin molding materialaccording to claim 1, wherein the inorganic filler (C) satisfies atleast one of the following conditions: the amount of particles having aparticle size of 12 μm or less is 50% or more by weight; the amount ofparticles having a particle size of 24 μm or less is 70% or more byweight; and the amount of particles having a particle size of 32 μm orless is 80% or more by weight; and the amount of particles having aparticle size of 48 μm or less is 90% or more by weight.
 11. Theencapsulating epoxy resin molding material according to any one ofclaims 1 to 3, wherein the average particle size of the inorganic filler(C) is 10 μm or less.
 12. The encapsulating epoxy resin molding materialaccording to any one of claims 1 to 3, wherein the specific surface areaof the inorganic filler (C) is from 3.5 to 5.5 m²/g.
 13. Theencapsulating epoxy resin molding material according to any one ofclaims 1 to 4, further comprising a coupling agent (D).
 14. Theencapsulating epoxy resin molding material according to claim 13,wherein the coupling agent (D) comprises (D2) a silane coupling agenthaving a secondary amino group.
 15. The encapsulating epoxy resinmolding material according to claim 14, wherein the silane couplingagent (D2), which has the secondary amino group, comprises a compoundrepresented by the following general formula (I):

wherein R¹ is selected from a hydrogen atom, an alkyl group having 1 to6 carbon atoms, and an alkoxy group having 1 to 2 carbon atoms, R² isselected from an alkyl group having 1 to 6, and a phenyl group, R³represents a methyl or ethyl group, n represents an integer of 1 to 6,and m represents an integer of 1 to
 3. 16. The encapsulating epoxy resinmolding material according to any one of claims 1 to 4, furthercomprising a phosphorus compound (E).
 17. The encapsulating epoxy resinmolding material according to claim 16, wherein the phosphorus compound(E) comprises a phosphate.
 18. The encapsulating epoxy resin moldingmaterial according to claim 17, wherein the phosphate comprises acompound represented by the following general formula (II):

wherein eight R's, which may be the same or different, each represent analkyl group having 1 to 4, and Ar represents an aromatic ring.
 19. Theencapsulating epoxy resin molding material according to claim 16,wherein the phosphorus compound (E) comprises phosphine oxide.
 20. Theencapsulating epoxy resin molding material according to claim 19,wherein the phosphine oxide comprises a compound represented by thefollowing general formula (III):

wherein R¹, R² and R³, which may be the same or different, eachrepresent a substituted or unsubstituted alkyl group having 1 to 10carbon atoms, an aryl group, an aralkyl group, or a hydrogen atomprovided that the case that all of R¹, R² and R³ are hydrogen atoms isexcluded.
 21. The encapsulating epoxy resin molding material accordingto any one of claims 1 to 3, which has one or more of the followingstructures (a1) to (f1): (a1) a structure wherein a bump height of aflip chip is 150 μm or less, (b1) a structure wherein a bump pitch ofthe flip chip is 500 μm or less, (c1) a structure wherein an area of asemiconductor chip is 25 mm² or more, (d1) a structure wherein athickness of a package, in which the semiconductor chip is disposed on amounting substrate, is 2 mm or less, (e1) a structure wherein the flipchip has 100 or more bumps, and (f1) a structure wherein a thickness ofan air vent when the material is molded is 40 μm or less.
 22. Theencapsulating epoxy resin molding material according to any one ofclaims 1 to 3, which has one or more of the following structures (a2) to(f2): (a2) a structure wherein a bump height of a flip chip is 100 μm orless, (b2) a structure wherein a bump pitch of the flip chip is 400 μmor less, (c2) a structure wherein an area of a semiconductor chip is 50mm² or more, (d2) a structure wherein a thickness of a package, in whichthe semiconductor chip is disposed on a mounting substrate, is 1.5 mm orless, (e2) a structure wherein the flip chip has 150 or more bumps, and(f2) a structure wherein a thickness of an air vent when the material ismolded is 30 μm or less.
 23. The encapsulating epoxy resin moldingmaterial according to claim 13, wherein the filler coverage ratio of thecoupling agent (D) is from 0.3 to 1.0.
 24. The encapsulating epoxy resinmolding material according to claim 13, wherein the heating reductionratio after heating at 200° C./hour is 0.25% or less by weight.
 25. Theencapsulating epoxy resin molding material according to claim 23,wherein the heating reduction ratio after heating at 200° C./hour is0.25% or less by weight.
 26. The encapsulating epoxy resin moldingmaterial according to claim 4, wherein the epoxy resin molding materialis applied to a semiconductor device having one or more of the followingstructures (c1), (d1) and (g1): (c1) a structure wherein an area of asemiconductor chip is 25 mm² or more, (d1) a structure wherein athickness of a package, in which the semiconductor chip is disposed on amounting substrate, is 2 mm or less, and (g1) a structure wherein theencapsulating-material molded area based on a package-molding method is3000 mm² or more.
 27. The encapsulating epoxy resin molding materialaccording to claim 4, wherein the epoxy resin molding material isapplied to a semiconductor device having one or more of the followingstructures (c2), (d2) and (g2): (c2) a structure wherein an area of asemiconductor chip is 50 mm² or more, (d2) a structure wherein athickness of a package, in which the semiconductor chip is disposed on amounting substrate, is 1.5 mm or less, and (g2) a structure wherein theencapsulating-material molded area based on a package-molding method is5000 mm² or more.
 28. The encapsulating epoxy resin molding materialaccording to claim 4, wherein the warp of a semiconductor device is 5.0mm or less.
 29. The encapsulating epoxy resin molding material accordingto claim 4, wherein the warp of a semiconductor device is 2.0 mm orless.
 30. The encapsulating epoxy resin molding material according toclaim 4, wherein the content by percentage of the inorganic filler (C)is from 70 to 90% by weight of the epoxy resin molding material.
 31. Asemiconductor device encapsulated by an encapsulating epoxy resinmolding material comprising (A) an epoxy resin, (B) a curing agent, and(C) an inorganic filler.
 32. The semiconductor device according to claim29, including one or more of the following structures (a1) to (f1): (a1)a structure wherein a bump height of a flip chip is 150 μm or less, (b1)a structure wherein a bump pitch of the flip chip is 500 μm or less,(c1) a structure wherein an area of a semiconductor chip is 25 mm² ormore, (d1) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 2 mm or less,(e1) a structure wherein the flip chip has 100 or more bumps, and (f1) astructure wherein a thickness of an air vent when the material is moldedis 40 μm or less.
 33. The semiconductor device according to claim 29,including one or more of the following structures (a2) to (f2): (a2) astructure wherein a bump height of a flip chip is 100 μm or less, (b2) astructure wherein a bump pitch of the flip chip is 400 μm or less, (c2)a structure wherein an area of a semiconductor chip is 50 mm² or more,(d2) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 1.5 mm orless, (e2) a structure wherein the flip chip has 150 or more bumps, and(f2) a structure wherein a thickness of an air vent when the material ismolded is 30 μm or less.
 34. The semiconductor device according to claim29, including one or more of the following structures (c1), (d1) and(g1) (c1) a structure wherein an area of a semiconductor chip is 25 mm²or more, (d1) a structure wherein a thickness of a package, in which thesemiconductor chip is disposed on a mounting substrate, is 2 mm or less,and (g1) a structure wherein the encapsulating-material molded areabased on a package-molding method is 3000 mm² or more.
 35. Thesemiconductor device according to claim 29, including one or more of thefollowing structures (c2), (d2) and (g2) (c2) a structure wherein anarea of a semiconductor chip is 50 mm² or more, (d2) a structure whereina thickness of a package, in which the semiconductor chip is disposed ona mounting substrate, is 1.5 mm or less, and (g2) a structure whereinthe encapsulating-material molded area based on a package-molding methodis 5000 mm² or more.